No design advice here; I'm a total disaster at picking colors. But I do have a question..
Darker colors retain heat more, and lighter colors reflect. Might the choice of a particular color, light vs dark, affect the interior temperature of the house in a way that's undesirable? So many factors influence what feels comfortable in the house. If you have lots of deciduous trees that keep you cool in summer, then maybe a darker color to retain heat in the winter would be good. Or maybe you have not a lot of tree protection and need to keep things cool in the summer.