3 in 1 modular building and madusa cement

i recived the walthers 3 in 1 building and madusa cement plant for christmas. they both seem like great kits, but i dont know the color i need to paint the 3 in 1 kit as the “expanded L” shown on the box. i dont have an airbrush. also, what color should i paint the silos on the cement plant?

dum question-- any other cars than covered hoppers that would come to the cement plant?

thanx
GEARHEAD426
happy holidays.

[8]

99 cent grey primer or flat white will work fine