Go for it! I had a bright red case for my phone for some time. Looked great, a nice little splash of color, also worked well with the company I was working for at that time (brand color was red, too).

I've changed phones since then and at some time found red "too much", so I went with a black case because I thought I needed to look more serious. Should revisit that thought, especially when talking about phone cases... :-D