Neutrals and muted tones always photograph well. So a light/pastel blue would photograph better than a cobalt blue, for example. Olive green, white, light blue, denim, browns and tans, and black are always winners. Small prints photograph well too, like small florals, cheetah, or small stripes. Avoid large prints, bigger than the size of your hand, just because the prints will sometimes detract from the person being photographed. Overall though, comfy is key!