Color codes of items

I’m trying to work out which weapons in inventory are usable. I understand the difference between weapons which are listed green, red, and gray.

However, many weapons are listed dark gray which appears to mean they won’t fit in any pocket.

This is a PITA because I have to actually pick up each weapon to see whether I have the ammo or magazine for this weapon.

Am I missing something? Is there a quicker way of seeing which weapons are usable?