So pretty simple TUT has I did in the bo3 section.
-Start cheat engine in multiplayer where you can see your classes.
-Name your classes one whatever name you want (exemple COUCOU)
-In cheat engine "value type" put string
-Search for the value "COUCOU"
-You should have a certain amount of results
-Rename that class to something else (exemple ALLO)
-Look for value "ALLO" and hit next scan
-You should have only 4 value now
-Add them to the address tab and change all of their value to what you want (exemple ^1I ^3<3^5CHEAT)
-Freeze them real quick close the classes section in game and reopen it to see if there is color on the class now
-Copy the colored class to all the other and here you go !
^1 - RED
^2 - GREEN
^3 - YELLOW
^4 - BLUE
^5 - CYAN
^6 - PINK
^7 - WHITE
^8 - DEFAULT MAP COLOR
^9 - GREY OR DEFAULT MAP COLOR
^0 - BLACK
If for any reason after doing the colored classes you can not join a multiplayer match (session lost, etc) remove the colored classes. should fix it