Themes and Color Schemes

When entering a competition, it seems the more "upscale" the affair, the less color is used. Why? I know how to compose and I did plenty of black and white for years, it was the fundamentals course after all! I just submitted for a juried exhibition about death and all that goes with it - so I sorta played it safe and submitted very subdued image colors with sepia added. I'm not sure if they really were my best images but I'm not going to be the judge of that after all. The top photo is the one I submitted.