In Killing Floor 2 I generally play as a medic, and while using medic guns I regularly see a blue highlight appear around my red dot sight. It lasts a short time and then disappears with no noticeable changes to the gun.
Normal crosshair on the left, extra detail surrounding the red dot on the right
This doesn't seem to correspond to wether I'm killing, the ammo capacity shown next to it or any other reported data. But it also doesn't seem to alter how the weapon functions? Maybe it's to do with the medic darts? But I can shoot them both with it visible and without.
Is it purely graphical, or does it mean something I've missed?