more pics, this time touching up the yellow in his vest. i used waterbased artists acrylics for this, carefully brushing the paint in, building up the thickness while checking with a light behind the glass to make sure the translucency matched ok. I wasnt sure how well this would look initially, but it worked out well 
The colour i used is called 'Cadmium Yellow" and matched really well.

Once that had dried i sprayed a couple of light coats of flat white on.