Re: specific coloring of diary calendar entries

[Richard Stallman]

      This is done via "color tags" -- a string
    that looks like "[color:blue]" (without the quotes, and blue can be any
    standard X color).

This is an ok feature, but it would be more useful if these tags
can specify a semantic category whose visual presentation is
defined elsewhere.

    If a date matches more than one entry, the FIRST matching entry's color is
    used for the date.

For explicit color tags, that's the best you can do.  But when using
semantic categories, you can do better.  You could pick the "most
important" semantic category according to a specified priority list,
from among those specified for the given date, and use its color.