Colorizing the index (1.3.23i)

[Peter Horst]

I know it's possible to color bits of the body of a message, using
pattern-matching, but is the same possible for parts of the index
display?  I was hoping to highlight just the number of messages in a
collapsed thread, & couldn't find any specific reference to it in the
manual. Also, my regex skills are weak.  I tried:

color index brightcyan default "(#[[:space:]]?[[:digit:]]{1,3})"

(Trying to capture the %M pattern).

Thanks.