Photographing a Painting Under Different Lighting Conditions

I was reading a thread on the Daily Painters Forum, about what lighting to use to photograph a painting for posting on the blog, and decided to experiment. The bottom version is photographed indoors, using the North light coming in through a window in my studio, supplemented by the overhead lighing and an extra light that I use to see what I'm painting, which uses regular lightbulbs. The top version is photographed outdoors in a shaded area. Clearly the indoor one is too warm and very different than the actual painting, but the outdoor one is appearing somewhat cooler and more blue than what I consider the real color(then again, maybe that is my computer monitor). The problem is that lots of times I finish a painting at night, and indoor lighting is the only game in town. Also I am painting under this lighting! What a difference. I think I will look into getting "natural light" indoor lighting for the studio.