What is the exact shade of green used on U.S. directional signs?

[Alaprine]

I seem to notice that older directional signs seem to use a darker shade of green, while newer installations use a brighter, more vibrant green (usually, these brighter signs also use the Clearview Typeface, but not all of them), although I'm not 100% sure if there indeed is a difference in color between the new and old signs. What do you guys think?

[ozarkman417]

I did this to get an approximate answer: Opened the MUTCD, took a screenshot of a BGS example, and plugged it in a program that can tell me what the shade of green it is.

Here is what it got me: R:0  G: 110  B: 81

Of course, it won't always stay that shade of green all the time, or states may do it differently.

Also, Welcome to AARoads!

[Scott5114]

I would think that any variance in sign color you've seen over the years is a combination of changes in sign substrate materials and vendors, age, and exposure to elements.

The official specification for color of traffic control devices is contained in the Federal Register. These specifications are done in terms of chromaticity and are likely to be too technical to be of much use to anyone who isn't a materials engineer.

As an addendum, FHWA also specifies a set of Pantone colors that approximate the chromaticity values. Pantone colors are used to specify spot colors in print materials, but FHWA cautions that these Pantone colors are not to be used for the manufacture of actual traffic control devices. The Pantone color number they specify for green is 342. If you are going to represent a sign graphic in a printed document like a brochure, this is the color you want.

RGB is not an appropriate color gamut to use to express the color of a traffic control device, because traffic control devices are physical objects and there is no consistent way to represent the color of a physical object on a monitor. Every monitor displays color differently, due to user settings and technical differences such as color temperature of the backlight (some tend more blue than others). However, if you must have an official-ish RGB color to use for a graphic, the RGB value closest to Pantone 342C is #006747.

[jeffandnicole]

I did this to get an approximate answer: Opened the MUTCD, took a screenshot of a BGS example, and plugged it in a program that can tell me what the shade of green it is.

Here is what it got me: R:0  G: 110  B: 81

Of course, it won't always stay that shade of green all the time, or states may do it differently.

There would automatically be several variations to that:  Your monitor and programs will pick up shades of color differently than other monitors or your phone.  Also, the color of the sign will change over the years.  Heck, the color of the sign will change hourly!  A picture of a sign taken in the morning with the sun facing it will appear brighter in a picture than a picture of a sign taken in the afternoon with the sun at a different angle, which will be different when in darkness, moonlight, conventual lighting or LED lighting.

[ozarkman417]

I did this to get an approximate answer: Opened the MUTCD, took a screenshot of a BGS example, and plugged it in a program that can tell me what the shade of green it is.

Here is what it got me: R:0  G: 110  B: 81

Of course, it won't always stay that shade of green all the time, or states may do it differently.

There would automatically be several variations to that:  Your monitor and programs will pick up shades of color differently than other monitors or your phone.  Also, the color of the sign will change over the years.  Heck, the color of the sign will change hourly!  A picture of a sign taken in the morning with the sun facing it will appear brighter in a picture than a picture of a sign taken in the afternoon with the sun at a different angle, which will be different when in darkness, moonlight, conventual lighting or LED lighting.

I just used the color selector on paint.net, so that shouldn't be affected by the monitor. To confirm this, I tried it at a different time of day and on a completely  different computer and screen, and I still got 0, 110, 81.

[Scott5114]

Yes, but what 0, 110, 81 means will differ based on every monitor.

[sparker]

Yes, but what 0, 110, 81 means will differ based on every monitor.

True -- but when it comes to paint/stain/anodization colors applied to a surface, the ratios, signified by the 0, 110, 81 will differ.  That formula means:  zero parts red (generally what one would call "fire-engine red"), 110 parts green, and 81 parts standard cobalt blue.   Greens, as far as paint goes, vary all over the map; green paint is a mixture of blue and yellow (generally "armour" yellow -- the color seen on Union Pacific locomotives); it can vary from bright green (more yellow) to grass green (usually a 50/50 mix) or forest green, which itself can have some white or black mixed in to lighten or darken it -- but generally less yellow in that case.  Caltrans used a "medium forest green", which itself was, in terms of percentage, 35 yellow, 49 blue, 8 white, and 8 black.  That created a medium-brightness forest green with a bit of "graying" to combat eye fatigue.  Most of the old button-copy/porcelain signs used that mixture, which responded well to the florescent light used on overhead signs until reflective sheeting became the norm, at which the signs became more or less "grass green" rather than the medium forest green they had been previously. 

My late mother was an animation artist at Disney for 40 years; she ended up as lead technician in the "color lab", where they mixed paint to order for their animated features and TV production (she retired in 1983).  She had the ability to look at a painted surface (structure, car, sign, etc.) and rattle off the ratios of the various primary colors used to formulate the various shadings used on the clear mylar "cels" (cellulose in the old days) used in the process.  One day while driving her around after retirement, I asked her if she could figure out the color ratio on older BGS (IIRC we were on I-80 between Fairfield and Sacramento, which had plenty of old porcelain through the '80's and '90's).  After about 10-12 miles worth of signs, she said "50 blue, 35 yellow, with 15 gray, which is why they look so dull!"  I asked my Caltrans engineer cousin if he could look up the exact formula they used -- and a few days later he responded with the info I related earlier.  She was damn close!  I'm reasonably good at that sort of thing, but I don't hold a candle to her!   

[StogieGuy7]

This is a great question and I'm surprised that there doesn't seem to be an easy answer (as yet).  I know that I don't have one.  However, I can tell you that the green color of BGS' has lightened a lot over the past 50 years.  A darker shade of green was more common during the 1960's and early 1970's; some tollways still had black BGS'.  That green has lightened over the years, especially the case now that the green base is reflective. In the (distant) past, only the button copy was reflective so a darker non-reflective background color was better.  Now that it's all reflective, that lighter green enhances the lettering without overloading the eyes with brightness. 

Anyhow, those are my basic observations. However, I am sure that there is a far more technically correct manner in which to explain this evolution which some of the experts around here can enlighten us with.

[thspfc]

It would be somewhere between yellow and blue.

[sparker]

This is a great question and I'm surprised that there doesn't seem to be an easy answer (as yet).  I know that I don't have one.  However, I can tell you that the green color of BGS' has lightened a lot over the past 50 years.  A darker shade of green was more common during the 1960's and early 1970's; some tollways still had black BGS'.  That green has lightened over the years, especially the case now that the green base is reflective. In the (distant) past, only the button copy was reflective so a darker non-reflective background color was better.  Now that it's all reflective, that lighter green enhances the lettering without overloading the eyes with brightness. 

Anyhow, those are my basic observations. However, I am sure that there is a far more technically correct manner in which to explain this evolution which some of the experts around here can enlighten us with.

The "dulled forest green" dicussed in my previous post was instituted in the late 50's to be easier on drivers' eyes than the white-on-black signage previously the standard in many states.  Because overhead signs were invariably lit with florescent lighting, which tended to lighten the signs' aspect, they were painted a slightly darker shade of green so as to make the white lettering on the signs stand out at night.  Of course, unlit roadside BGS's featured button-copy, as did unlit "upcoming exit" signage.  But a couple of decades back when many DOT's , including our own out here in CA, decided to eliminate electric illumination for overhead signage, substituting reflective sheeting, they opted for a brighter "grass" green, which worked better with the halogen and LED automotive headlights becoming standard in vehicles about that time.  But the darker green mostly painted signs had a good 40-odd year run of being the default standard before the brighter hues started appearing en masse!

[STLmapboy]

This is a great question and I'm surprised that there doesn't seem to be an easy answer (as yet).  I know that I don't have one.  However, I can tell you that the green color of BGS' has lightened a lot over the past 50 years.  A darker shade of green was more common during the 1960's and early 1970's; some tollways still had black BGS'.  That green has lightened over the years, especially the case now that the green base is reflective. In the (distant) past, only the button copy was reflective so a darker non-reflective background color was better.  Now that it's all reflective, that lighter green enhances the lettering without overloading the eyes with brightness. 

Anyhow, those are my basic observations. However, I am sure that there is a far more technically correct manner in which to explain this evolution which some of the experts around here can enlighten us with.

Are there any color photos of black BGSs out there?

[sparker]

This is a great question and I'm surprised that there doesn't seem to be an easy answer (as yet).  I know that I don't have one.  However, I can tell you that the green color of BGS' has lightened a lot over the past 50 years.  A darker shade of green was more common during the 1960's and early 1970's; some tollways still had black BGS'.  That green has lightened over the years, especially the case now that the green base is reflective. In the (distant) past, only the button copy was reflective so a darker non-reflective background color was better.  Now that it's all reflective, that lighter green enhances the lettering without overloading the eyes with brightness. 

Anyhow, those are my basic observations. However, I am sure that there is a far more technically correct manner in which to explain this evolution which some of the experts around here can enlighten us with.

Are there any color photos of black BGSs out there?

From the usual CA suspect -- back issues of CHPW -- not really; all their photography (except for the cover photo) was B&W -- plenty of "BBS" pix there, but likely on Plus-X or Tri-X stock.  That never changed until the consumer-oriented 1966 edition (their final one) was published -- more of a travel guide than technically informative.   If someone out there has color pix that show white-on-black overhead signage, I for one would like to see that.  Actually, it's not terribly hard to discern newer dark green signs from black even on original B&W photos such as used in CHPW -- the black signs were very "jet black" and distinctly stood out from the green ones, which showed up as "charcoal gray" or, in broad daylight, more of a slate gray tone.  I remember back in my home town of Glendale, the first segment of the Golden State (future I-5 but then signed as US 99/6) freeway (1957) featured black overhead signs; that continued with the early 1959 extension through downtown Burbank.  Two years later, both south extensions (to US 66/"Pasadena Freeway) and north ones (out to Lankershim Blvd. in Sun Valley) featured green signage.  The black signs on the original section lasted until about 1963-64, when they were replaced over about a years' time with newer green signs -- which actually featured white shields for both state and US highways on the signage itself (cf. the original SSR 134/Ventura Freeway junction, which originally only had NB>WB and EB>SB movents).  By the time the eastward section of the CA 134/Ventura Freeway was opened through Glendale in 1969, the signs featured the white-outline on green background state shields to match the '64-issue "new" green state shields. 

[J N Winkler]

The "dulled forest green" dicussed in my previous post was instituted in the late 50's to be easier on drivers' eyes than the white-on-black signage previously the standard in many states.  Because overhead signs were invariably lit with florescent lighting, which tended to lighten the signs' aspect, they were painted a slightly darker shade of green so as to make the white lettering on the signs stand out at night.  Of course, unlit roadside BGS's featured button-copy, as did unlit "upcoming exit" signage.  But a couple of decades back when many DOT's , including our own out here in CA, decided to eliminate electric illumination for overhead signage, substituting reflective sheeting, they opted for a brighter "grass" green, which worked better with the halogen and LED automotive headlights becoming standard in vehicles about that time.  But the darker green mostly painted signs had a good 40-odd year run of being the default standard before the brighter hues started appearing en masse!

My understanding is that the darker green is associated with porcelain enamel on steel, for which the more or less exclusive vendor in California was Cameo.  Early in the 1970's (per file correspondence now at the Caltrans History Library in Sacramento), Caltrans felt pressed to match federal green (with some compromise in terms of increased variation in color from sign to sign) and was also moving from steel to aluminum as the substrate material.  I believe this is when opaque coated background first came on the scene.  The lights-off initiative came later in the 1970's, due to the energy crisis, and resulted in epoxied-on reflectors being retrofitted to foreground elements on porcelain enamel on steel signs.

Are there any color photos of black BGSs out there?

A few (ultimately sourced, I believe, to scanned slides) have been posted on Facebook, notably in the Los Angeles Freeways group.  When they are taken with the sun over the photographer's shoulder (the optimum position for landscape photography), the visual effect is very much like modern weight station signs, which have white reflectorized legend on nonreflective black background.  However, many of these signs were unbordered, especially in the early days.

There is some controversy about whether Caltrans ever produced and erected G23 interchange sequence signs with green background and underlined miles and tenths.  Caltrans is known to have adopted green background and vulgar fractions both in 1958, but it is unclear how the two changes were sequenced.  Some have claimed to have seen color pictures of miles and tenths on green, but I personally never have.

[sparker]

The "dulled forest green" dicussed in my previous post was instituted in the late 50's to be easier on drivers' eyes than the white-on-black signage previously the standard in many states.  Because overhead signs were invariably lit with florescent lighting, which tended to lighten the signs' aspect, they were painted a slightly darker shade of green so as to make the white lettering on the signs stand out at night.  Of course, unlit roadside BGS's featured button-copy, as did unlit "upcoming exit" signage.  But a couple of decades back when many DOT's , including our own out here in CA, decided to eliminate electric illumination for overhead signage, substituting reflective sheeting, they opted for a brighter "grass" green, which worked better with the halogen and LED automotive headlights becoming standard in vehicles about that time.  But the darker green mostly painted signs had a good 40-odd year run of being the default standard before the brighter hues started appearing en masse!

My understanding is that the darker green is associated with porcelain enamel on steel, for which the more or less exclusive vendor in California was Cameo.  Early in the 1970's (per file correspondence now at the Caltrans History Library in Sacramento), Caltrans felt pressed to match federal green (with some compromise in terms of increased variation in color from sign to sign) and was also moving from steel to aluminum as the substrate material.  I believe this is when opaque coated background first came on the scene.  The lights-off initiative came later in the 1970's, due to the energy crisis, and resulted in epoxied-on reflectors being retrofitted to foreground elements on porcelain enamel on steel signs.

Are there any color photos of black BGSs out there?

A few (ultimately sourced, I believe, to scanned slides) have been posted on Facebook, notably in the Los Angeles Freeways group.  When they are taken with the sun over the photographer's shoulder (the optimum position for landscape photography), the visual effect is very much like modern weight station signs, which have white reflectorized legend on nonreflective black background.  However, many of these signs were unbordered, especially in the early days.

There is some controversy about whether Caltrans ever produced and erected G23 interchange sequence signs with green background and underlined miles and tenths.  Caltrans is known to have adopted green background and vulgar fractions both in 1958, but it is unclear how the two changes were sequenced.  Some have claimed to have seen color pictures of miles and tenths on green, but I personally never have.

My late father never missed the opportunity to check out new L.A.-area freeways after they were opened --- dating from my earliest lasting memories in the mid-50's through my high-school years in the early/mid-60's.  From all those travels, I don't ever recall advance-exit signage with mileage stated in decimal 10ths existing on any signage other than white-on-black.  Most of that signage was replaced with green by the mid-to-late '60's; the one "straggler" that I recall was US 101 in Ventura County between the bottom of Conejo Grade and the (then) CA 1/Oxnard Blvd. exit in Oxnard; those black signs, including the decimal-mileage ones, persisted until at least the late '70's -- about the time the freeway was widened to 6 lanes.