Kask można pomalować lakierami wodnymi bez obawy o rozpuszczalniki.

Mój skończył na takim etapie
http://images40.fotosik.pl/336/4a1878247b9de070med.jpg

Cytat z manuala Araia:

"If painting your helmet, be sure to protect the entire inside
of the helmet from the paint spray by masking all openings
with paper and tape as paint can adversely effect the
shock absorbing liner and plastic components. Use only
air-drying paint, not paints that require heat curing."

Czyli dokladnie maskowac i malowac. :)