Unique Background Colors for Calendars

[Grizz952]

Ongoing struggle to understand what ‘can’ and ‘cannot’ be done within basic modules. I currently have four calendars loaded in the basic ‘calendar’ module. MM is retrieving information appropriately. I have the text color set differently for each calendar. What I would like to do is set a unique ‘background color’ for each calendar. Possible? Recommendations?

[sdetweil]

@Grizz952 not built in,
css can set background-color

may take multiple clauses