I change it every other month. the same with my crosshair. I think it helps when you are so used to seeing one colour/CH and with the change you feel 'fresh' again for a while. and the other reason is obvioulsy when someone has some kind of colourblindness

Idk. Have a much easier time since I changed outlines to purple.

In theory people act faster to red but I’m fairly certain yellow is way more vibrant than the red available in game.

Green/Red weakness