Coloring pieces of messages in Gnus

[Peter Anderson]

I'm a noob.  I've looked around and think I've found parts of the answer
but can't find any good examples.

I want to use a regex to change the color of some aspects of articles.
I have a group called git-commit.  For articles in that group I would
like any line that starts with "---" to be red and any line that starts
with "+++" to be green. (the whole line)

Another group has Help-desk tickets in it and it will have line similar
to:

   blah blah blah Assigned: Peter

I want to be able to make the word following "Assigned:" (in this case
"Peter") stand out by changing its color or some attribute.

I think I need to define a function and then use gnus-part-display-hook
but the syntax of it all has eluded me so far.

Thanks so much,

Peter