Many have had good luck painting them white. Mine cracked due to poor workmanship and I replaced with White Lexan. I can hardly tell the difference in the amount of light coming through, and it is much cooler now.
'04 GMC Sierra 2500HD, CCSB, D/A, MaxBrake, B&W Companion, Retrax Pro, AR Power Steps
2013 Rockwood 8289WS w/Diamond pkg
1969 Camaro RS/SS Convertible
Dad's old 1968 Empi Imp (recently recovered from under 21 years worth of boxes/dust)