There is a guy that goes by the user name "Chopper" who owns an auto body shop who can answer any painting questions for you better than anyone else - he is very forthcoming with information. You could send him a PM and I am sure he would respond very soon. Sorry to volunteer you Chopper!
Something some folks have done is remove the red parts of their seats and have an interior shop sew in yellow to match their Proton's skin - looks real trick! So if you are going to take the painting route you could take it a step further by doing that. A search in the gallery may show you the pics of the yellow trimmed interior... Happy hunting!!!
Sent from my "two hands on a keyboard"