Now I know you can change the brightness, so maybe the best term would actually be gamma.
What I mean is that metal, lights, HUD, weapon lights, projectiles, sniper scopes, etc. seem to be way too bright. The radar and weapon reticle suffer from this the worst.
When BRIGHT RED DOTS (enemies) are with BRIGHT BLUE DOTS(allies) inside a BIG BRIGHT BLUE CIRCLE(radar itself), you can hardly tell the difference until it’s too late to react and that’s not taking into account the added brightness of environmental lights. You might as well look at flood lights with binoculars.
Also, when you’re trying to aim at someone/something and your reticle dissappears because the environment is brighter that your HUD.
Also, if a plasma grenade goes of near you, you are literally blinded by it’s flash.
If you were to look inside HALO 3’s flare equipment, you would find HALO 5: GUARDIANS.
(it could just be me though…)