system
Given the following post, respond as if you're commenting on Reddit:
human
[Warhammer 40k] Why don't space marines use camouflage?

Of all the space marines, scouts appear to be the only ones to use camo from time to time. Why wouldn't any other space marine attempt to use camouflage in attempts to blend in? The imperial guard definitely use it to their advantage by having it on all of their equipment.
gpt
The vast majority of the time, the honoured Astartes do not engage in the types of combat where visual camouflage would provide meaningful advantages. The Astartes are masters at assaulting the enemy, and their mobility and control of the flow of battle, whether travelling on foot, in drop pods, or in vehicles limits the need for stealth. Any foe capable of putting them on the defensive would not fall for simple splotches of paint. The Arstartes are the ceramite fist of humanity, and whether striking or parrying a blow, it should loudly resonate through the wretched damned soul of our foes. Leave the subtlety to us mere mortals.