One solution that works for coloring all sorts of text, not just logfiles, is a Python tool, 'colout'.
pip install colout
myprocess | colout REGEX_WITH_GROUPS color1,color2... [attr1,attr2...]
Where any text in the output of 'myprocess' which matches group 1 of the regex will be colored with color1, group 2 with color2, etc.
tail -f /var/log/mylogfile | colout '^(\w+ \d+ [\d:]+)|(\w+\.py:\d+ .+\(\)): (.+)$' white,black,cyan bold,bold,normal
i.e. the first regex group (parens) matches the initial date in the logfile, the second group matches a python filename, line number and function name, and the third group matches the log message that comes after that. This looks like:
Note that lines or parts of lines which don't match any of my regex are still echoed, so this isn't like 'grep --color' - nothing is filtered out of the output.
Obviously this is flexible enough that you can use it with any process, not just tailing logfiles. I usually just whip up a new regex on the fly any time I want to colorize something. For this reason, I prefer colout to any custom logfile-coloring tool, because I only need to learn one tool, regardless of what I'm coloring: logging, test output, syntax highlighting snippets of code in the terminal, etc.