If you'd like some ideas, I believe I do have a crafty way to add color-picker options for these.
~B

Unfortunately it is not possible. Cars and tanks only change color when a player enters. Without a player, they are always white (colorless).

True but there is a mod that does allow color permanence in any of these vehicles. It creates an object that goes in the trunk. If that could be "color-picker-orized" then it'd be set, no?

Which mod are you talking about? I may take a look on it.

ColorEquipment

https://mods.factorio.com/mods/folk/folk-colorequipment

Haven't tried the mod yet, but according to its description:
"It works on cars/tanks/etc in the sense that they inherit their color from the player, but you can not apply a color directly to a car/tank unfortunately. You can insert the item, but it won't do anything."

So I guess it won't work.

It's a color tile that you put in the trunk so that your car doesn't have to be the same color as your character.

If you added color-picker to make the special tile, job done...

Just a suggestion...No big deal. :p

That's not possible. That mod does the coloring by creating one equipment for each color. If we apply color picker to it, even if we don't support alpha channel, we will need 16777216 (256 for Red * 256 for Green * 256 for Blue) different color equipments, which means your computer will explode. lol

Ah, got it!