REAPER will automatically add icons and/or apply colors to any track, region or marker whenever the conditions specified in your custom settings are met.
Examples of use
Improve visibility, get a nicer visual organisation of your projects. Have a clear vision of relationships between tracks. Define custom colors wether tracks are folders, children, having receives or sends, being unnamed or containing specific words (ie tracks with "bass" in their name can be colored in orange)
In my gif example below:
any folder track will get a random color and a "buss" icon
any children track will heritate it's parent color and get a children track icon
REAPER + SWS
Set the behaviour in the SWS Auto Color/Icon window