One is that the B66 has the Zil tent with the same Zil color... It should be green instead of blue.

Second one is that the C4320 has a orange tanker, but the 255 has a green one. Why not put the green one in the green trucks?

I think this is not necessary. But the tanker for the Zil131 looks really ugly. Like in the demo from the last century.
Needs really some cosmetics.

the orange tanker is the trailer tanker, the green one is directly attached. but yeah orange tanker is clearly old model/textures, needs updated version. i'm guessing it's just not used very much so they didn't bother working on it.

some of the vehicles also are still using the old version of the maintenance cart. the new version looks much better but i guess it does not fit on all trucks