That's spooky Our smart repairer guy was in at work (he painted my air box) He loaned me some piaggio swatches I matched the colour up last night and came up wth ARANCIO STORM 816 Or MANGO 806
Although my air box may not be an exact match for an original it's pretty close and looks very good Pity I have k&n"s on !
Yes they are fibreglass and I think you're right about the colour. I was tempted to spray mine to match to bodywork but decided to stick with orange for originality.
Right, I've just been in to the local paint suppliers and looked at the orange swatch cards. They have several that are very close but I settled on Piaggio 926 Arancio. So you can decide yourself you can see it on the website linked below (third row down);