Sometimes colours of weapon can be crucial for aesthetic senses of players.
For instance, black variant of ARCO fits with Katiba rifles. Also, urban-camoed variant (or more cheap khaki-black variant) of Rahim sniper rifle and RPG-42 will look great with CSAT Urban soldiers.
Either way, black version of Mk17 Holosight is looking great with black MX'es etc.
Could you add it?