This was nerfed due to complaints by PvPers and hardcore RPers.
Not likely to ever come back unfortunately.
I'm assuming you are using the word nerf ironically since changing colors of weapons isn't related to player combat power.
Its not likely to come back for the same reason there are limited colors in uniforms and ship customization. There is a fine line between customization and violating the restrictions placed on the game based in the IP owner's wishes. They walk right up to the line but pink disruptors is way over it.