K Rend

A friend of mine has had her exterior rendered with K render, with the sparkly little bits in it. This was done about 10 years ago. She now says that two of the elevations are becoming discoloured like a pink staining coming through. The render seems to be sound. Is there any particular product that can be painted on successfully ? Would it need to have any special sealer / primer first. Would a pliolite based paint be better ?
Advice welcome