It’s not because of wall-hack or cheating
In csgo, I got dumb dumb and used an external software to change my gun skin on my screen. Of course valve didn’t like that…..
In layman term :
It’s like ur gun skin base colour is green. I use a software to change it to gold.
People still see it as green on their screen, game still recognise it as green, but I see it as gold on my screen