REMEMBER, my model is a supposition about how i think looks.

The things to do for install new colors is:

Delete the default line of Bus colors

This one:
[[[ bus, 71,59, 75,59, 92,72, 47,74, 55,83, 59,83, 71,87, 82,87 ]]]

And put the new carcols line in the "Car4" section [under of all colors]

New line:
[[[ bus, 6,17,116,0, 42,94,49,0, 1,6,3,0, 93,12,4,0, 7,53,6,0, 38,37,40,0, 5,65,100,0, 44,2,122,0 ]]]

If you do right, the Dash-Hound will regconize the colors in the game (like photos)

Thank you for Download!
-Uk10r4


Ps: Some colors are been added by me!
2ndPs: Cheeeck bonus.