I would think violet is best for near blue, red, green and yellow. But white or orange could work maybe, if you have to. There are a limited number of colors, so I think you just need to find what 5 you can find. Few people will know what the color is supposed to be. But a black lance will be hard to see for sure.
NC Licensed Lead Pyrotechnics Operator - CDL w/ Hazmat
Burning the fuse at both ends...
It might be a bit overpowering, but if you used a massive amount of white (silver) you could make a black ring by utilizing the negative space.