This is a very simple fisher package which colorizes the output of man
which results in much nicer to read manual pages. It does so by simply setting some shell variables to colours. It's a shameless ripoff 😃 from omf-color-manual and was ported to fisher for use.
You should be able to install fish-color-manual
via fisher.
$ fisher add pcr910303/fish-color-manual
You can download conf.d/color-manual.fish
and source it from ~/.config/fish/config.fish
if you want, but why would you? If you're one of the ones that don't use fisher, going to the original repo will be more beneficial.