Yella
 

Surley the best way to solve your touch up problem would be to have it sprayed the correct colour - RED!:D

Paint!
 

I have a '98 916 BP Foggy Rep which had a respray to convert it to the replica, since owning it I have 'marvelled' at all the different shades of red you can get in different light and at different vauntage points! The bike looks like 3 different reds on one. It has not been down the road and is a mint 3200 miler! But I have never known a bike to play tricks with my mind!