I have been searching for new vinyl windows which according to my research is a better alternative to wood as long as its " high end vinyl". I have a question regarding the interior. My contractor who is a very nice man tells me his windows can be almost any color i want on the exterior only and the interior color options are limited.

why is it that they can color the exterior which is more exposed to rough conditions but they cant put any kind of coating on the interior other than a woodgrain laminate or white or beige, it makes absolutely no sense. Why cant they put the same coating they use on the outside on the inside? I realize you cant get dark color on both inside and outside but why not forest green on the interior and a white exterior? Can the pro's tell me why this is?