Quite to the contrary, pigment is what keeps plastics and paint safe from all but surface UV damage. Clear plastics, varnish etc. break down much faster from UV degrading the material thru and thru as opposed to surface only degradation of their pigmented counterparts. Crappy plasticizers leaching out of Spindly plastic too quickly is what causes the brittleness.
Heh! I've got a bare PEx prototype MoBo, does that count as clear!
) Nice one, hap, color me jealous as hell. :-/