How to write colorful?

Null's Clash
1

Here I saw someone can made that

Screenshot_20190621-222929
Screenshot_20190621-2229292190×1080 1.64 MB

I only know that <. cNUMBER>TEXT<./c>
But that is only one color!

How it works?

2

https://files.dnull.xyz/someshit.html
sorry but you cool men (што)