I found it!! What is make photon color turn black when use weapon camo.

alt textalt text

I found main problem that cause photon color of changeable camos go black. It will change to black only when you use any multi-type weapon camos that can use on problem camo type (In this case; wand). If use only single type camo or none-wand camo on all weapon, it will still show right photon color.

It might be a conflict with those camos or what you merged as the multi-weapon, since I also use a multi-camo that has a photon color (Mega Slash Edge) and I set it to rifles while I have a completely different camo for rods, both of these work properly on my rifle/rod multi-weapon.

I think is only certain camos that conflict with each other, I use Coated weapon and a different one with rifle and my rod photons continue to be normal