That would be rather hard to see on some resolutions/monitors and for most mercs they would only see the full black "I forget" version anyway.

Plus when you found a magazine, unless it was one of the clear plastic types, you shouldn't know what was loaded.

Since there's an ammo counter is there really a need for a graphic to show the gun is loaded? Just a symbol to show that the gun was unloaded without a magazine. Perhaps overlay the magazine outline from the pockets on the weapon when you eject the magazine.

Same system as now with the colour changing based on the visible loaded bullet, any further information requires the character to unload and reload the magazine. If any situation calls for the fog of war it's remembering which magazine has what load out.