This question is primarily about ranged weapon modifications as melee weapons/mods only correspond to one color - orange - but ranged corresponds to two - blue and purple.
When attaching a mod to a weapon, does the color of the modification bar on the mod need to match that of the weapon?
I presently believe that the bar color doesn't make a difference as long as the icon (melee/ranged) matches between the weapon and mod (and that the other rules/restrictions are followed such as number of bars and modification type [barrel, sight, etc]). This is because modification bar color is not mentioned as a restriction for usage anywhere that I was able to locate.
Thank you for your consideration! ^__^
Color matters. However there is only Orange (melee) and Blue (ranged). If you have Purple, sounds like a printing error (ink/toner running out) and should be treated as Blue.
Putting a Sight on your gaffi stick doesn't make any sense!