Makes it so that when you place colourable entities, they default to using the player colour.
In particular, all of the following will use the player's colour when placed:

• Cars and Tanks: as in Vanilla, they will update their colour to the colour of their driver (note that blueprints do not save the colour of these, so they will use the colour of the player that placed the blueprint, not the player that created it)

• Train Stops: as in Vanilla, the colours of a train stop placed via a blueprint/ctrl-c/ctrl-x will be preserved (unless the train stop never had it's colour set in the first place).

• Locomotives: similar to Train Stops, except that as in Vanilla, by default, the locomotive will automatically change colour when driving to a train stop (this can be turned of in the locomotive's GUI).

• Spidertrons: similar to Train Stops, except that as in Vanilla, the colours of spidertrons are saved when picked up and placed in your inventory

• Cargo Wagons and Fluid Wagons: if you have the Fluid Wagon Color Mask mod installed, these will behave like locomotives; otherwise they will remain uncoloured as in Vanilla.

• Turrets (except the Artillery Turret): these do not get modified by this mod, as Vanilla already sets their colour to the owning force (which may have a different colour to the player).

This mod should hopefully work with any other mod's that add new colourable entities, in particular, this mod will set the color field of any LuaEntity with no color (e.g. freshly placed Train Stops or Locomotives), an invisible colour (e.g. Cars and Tanks), or the default orange (e.g. Spidertrons).
If you don't like the way it works with another mod though, let me know in the discussion!