I prefered silver bodied film cams because it took them longer to get hot in the sun. Heat + Film = Bad pics.
If you really have to keep the camera sitting in one spot, such as on a tripod, throwing a white towel over it does a much better job than depending on surface coloring.
If you're in motion, such as walking around, it makes no difference.
By the way, the distinction has already been made between silver-painted plastic and true silver metal (usually brushed chrome). Brushed chrome is far, far more attractive than silver-painted plastic, and that distinction should be made.
Except perhaps for some silver painted plastic Rebels in later years, film cameras were brushed chrome metal (although the Canon AE-series cameras were brushed chrome metal-clad plastic).