Multitail is a command line tool primarily used to merge several log files. It is also capable of highlighting the output from one or more log files. In Ubuntu, you simply create or extend your multitail configuration in your home.
vi ~/.multitailrcand define there your custom color scheme named yourcolorscheme
colorscheme:yourcolorscheme cs_re:red,,bold:.*ERROR.* cs_re:green:INFO
When invoking multitail command, provide the designated color scheme (-cS) you want to use.
multitail -cS yourcolorscheme -f logs/server.logThanks to Gilles for the input.