I've seen only certain peices painted instead of the entire part (like the stripe of the missile being an different color then normal but the rest of the missile being the same color as the fuselage) like on the wasp, certain things have different arrangements for paint..(if any of this makes sense)..but
Go to paint (duh) and click “target”, there is
All
Primary
Trim 1
Trim 2
And trim 3
Oh