We could take log coloring a bit further.

The idea is to have regular expressions and color whatever matches. For
instance, it would be useful to color red everything starting with "ERROR" and
"CRIT" (nowadays aka "error" and "crit").

It should be configurable, i.e. let the user add regex-color mapping to a file.

It is important to reset back to the initial color at the end of the match, so
we need to keep track of the current color on the line.

It'd be good to allow more than eight colors we currently have.

I think I've seen once some utility which does this for syslog based logs.