what kind of job is it? I was on the academic job market last year and wore a basic black suit everywhere but had a few shirts. My basic shirt was a pink/black/white striped thing (a lot more professional than it sound) which I felt like added a little "pop" to my otherwise basic uniform.
But, when I interviewed someplace that had a school color I could work with, I added a touch of their school color if I had the shirt.