OEM Roms and Android Modding

Most Android OEMs have their own Android ROM.
Xiaomi has MIUI, Oppo has ColorOS, Realme has RealmeUI, Samsung has OneUI, etc.

Some people might enjoy these Android skins and use them on a daily basis, though, this generally cannot be recommended if you want to customize Android to it's fullest.
This is because most OEMs try to avoid users from rooting and modding their Android phone, like Xiaomi tries to detect Magisk in the System Security and Cleaning app.

Some OEM skins might also restrict applications from running in the background, you can check wether your OEM does this aggressively and how to bypass it on "Don't Kill My App!".

Outside of that, some OEM skins might have customization mods made specifically for them.
Here's a list of some that I know of:

(Paid entries in this list have a next to them

• CustoMIUIzer - Customize MIUI using LSPosed or other Xposed implementations.
• HEX Installer ( )
• Android 12 Repainter ( ) ← Works without root on Samsung, and partially without root on Pixel!
• Samsung Goodlock
  Samsung's goodlock is available per-region, specifically places like Canada, though you can install it on any version of OneUI no matter the region using "Nicelock" from the Google Play Store
  
  More will be added to the list soon…