Even your violet, green and blue lasers are invisible in space anyway. It's essentially a HUD effect, really.Since Laser Color denotes the actual TYPE of Laser being used in the Real World, I would caution all those "Immersion" focused players about buying these "FAKE" color options for their various laser weapons in the game.
I guess if you don't care about physics realism in the game, then it won't matter, but it is curious how Frontier puts so much effort into trying to do things according to real-world physics etc. and then does something like this.
A classic case of Elite Dangerous meets Arcade Game mechanics.