It would be called color and acts like deco. The 4 or three values would be R,G,B, Brightness (optional)
It would work like this:
!set color ttan 255,10,35,100
When using the command it would deco the element you use it on.
Mabye even add it to the PROP tool?
This would be usefull for quick deco-ing of your saves.
You can change RGB values in the deco editor! See that lone square in the middle of the deco editor? Click on that, and you'll see a color picker thing pop up. There you'll see some text fields where you can input R,G,B,A values and stuff.
There's already one -_-'
!set dcolor ELEM RRGGBBTT
Colors are in hexadecimal, ELEM means any element except VIRS and other states, TT means transparency