In my ~/.gitconfig I have

[color]
    pager = no

And I use vim as pager. It has built-in git log highlighting, so the output of git log looks like this:

However, glg output looks weird:

This happens because glg alias expands to git log --stat --color -p and --color param prevents color.ui = no in my ~/.gitconfig from working.

I think --color should be removed from all git log aliases in order to let user decide in his ~/.gitconfig whether to use colorized git log output or not.