What's the point of the custom colours and armour?

I was opening some REQ packs and I thought to myself what is the point of the customisation. On halo 4, there was Spartan ops, which allowed you and your friends, each with unique characters, to play as a squad in mission. There is free for all, that puts you up against other people, which shows your custom character.

in halo 5 I can only think of free for all.
I just want to be able to show off my awesome character that I know some people have spend a lot of actual money and Ingame to create.
What is the best way to do it that?