My Suggestion would be:
1. List 1-7 Genre colors in the skin, name them genre_1 to genre_7 (skinsettings.xml)
2. Map the standard/customized genre names (default, documentary, kids, ...) to the genre_1 to genre_7 in MediaPortal.xml
3. Map the EPG Genres to the standard/customized genres either in MediaPortal.xml (or even better in my opinion) in the TV Server Database.
1. List 1-7 Genre colors in the skin, name them genre_1 to genre_7 (skinsettings.xml)
2. Map the standard/customized genre names (default, documentary, kids, ...) to the genre_1 to genre_7 in MediaPortal.xml
3. Map the EPG Genres to the standard/customized genres either in MediaPortal.xml (or even better in my opinion) in the TV Server Database.