I could never figure this spell out, for this reason:
Quote:
Components V, S, M (red, yellow, and blue powder or colored sand)
If it was anything resembling an actual light display or a neural screw, it would be based in the colours that a person's light receptors recognize. It's not, so it needs to be a partially reflective surface, which doesn't fit at all with an illusion that can still be deployed in the dark.