It’s pretty difficult to spice up a black suit, as it’s not particularly versatile. I would keep the colors subtle and the accents minimal. Use your tie and your pocket square to add color, but don’t overdo it. Maybe stick with the basic shades of blue, dark green, grey, etc. While white shirts will generally look the best, you could also try some lightly patterned shirts - grids/panes, dark gingham, or glen checks.

Disclaimer: I try to avoid black suits in almost all instances.