As hemicyon says above you can you use favourites.
As you can "rename" actions in favourites,there is nothing to stop you having the same action with DIFFERENT colours. e.g. comment_RED and Comment_GREEN etc.
In my own case colours are used
1: to show the extent of a group (three different colours to allow for "nesting")
2: Status of action e.g. Debug or user input
3: type e.g. comment is always GREEN
A simple set of macros to set the colour quickly can be found at
Set KM Action Colour (Color).