Yeah, my door panels were like that, they are blue ones. Turned almost a green/aqua color from the sun, very chaulky.
I'm not a resto type of guy so I "Mickey Moused" it since I don't $$$ to spring for a new set. I basically scaped off as much chaulky stuff as I could and repainted it with Plasticote interior vinyl paint, which matched the blue very well. (By looking at the back side of the panel that wasn't exposed to the sun.
Yes, the texture is off in those areas but for me it was a quick fix without spending too much $$$.