I wrote some triggers to get colors when using iTerm2 (screenshot below) with Arista EOS but it should also work on Cisco IOSes with some minor tuning.
iTerm2 is a replacement for Terminal and the successor to iTerm. It works on Macs with macOS 10.14 or newer. It allows you to create Triggers. Triggers watch for text matching a regular expression to arrive in a terminal session and then perform an action in response. You can import triggers from a file/profile but you can configure them on "Preferences, Profile, Advanced, Edit Triggers".
The whole options are detailed in the official documentation for triggers.
errors on interface
These regexp have been split to 3 lines to be easy to read
Background in red, text in white.
BGP sessions status
If you are using observium syntax...
Set colors on logs lines/patterns
You get the idea :)