Which states used yellow / gold state state highway shields in the early days?

[Mdcastle]

So far I've come up with:

New England in general (through 1927)
Maine (through 1934)
Minnesota (through 1933)
Ohio
Alabama
Missouri
Iowa
Oklahoma
Kansas, of course
Wyoming
California

Alternatively would be helpful to know which states were always white.

[SkyPesos]

Ohio used it until 1927, then switched to black on white.

Note that Missouri's first state route sign (with the gold) is an oval shape, nothing like the state outline it uses after that.

[Mapmikey]

North Carolina and Virginia have always been black and white

[Quillz]

When did California ever have yellow miner spades?