Not that it's much consolation to you, but my dealer refused to colour code my mirrors/sills saying that they had so much trouble with the paint coming off that it wasn't worth the aggravation.

I have had MY99 DBM since March, had it fully colour coded before collection. I have noticed a section about the size of 1pence on both sills at front, just where you feet exit the car (must stop wearing those dam stilletoes!). The paint looks like it could be peeled away around the chip, like if you gloss wood without undercoat,ie the paint is not keyed to the sills, if that makes sense.
Anyone else had same/similar problems with colour coded bits

Sounds as if they haven't used the correct plastic primmer. I painted my DBM over a year ago with no problems.
The sills do tend to get scuffed with shoes though, and its probably more noticeable on the darker colours.
I gave mine about 5 coats of lacquer, so all I do is rub them back with 1200 wet/dry, then use cutting polish to make them look like new again.