Re: `git log --graph` with multiple roots is confusing

> I sometimes pull things in from unrelated repositories to rebase or
> cherry-pick items from a different line of development. I've done this
> to bring isolated features into a project in their own feature
> branches with their full development histories, and also to extract
> lines of development out to their own project, with their histories
> intact. These are usually not connected commits, but things I have to
> track down across time with `git log -S` and friends.
> 
> When I `git remote add otherrepo <url>`, then view things with my
> aliased `git log --oneline --all --graph --decorate` alias, I'm
> usually immediately straining to figure out what's what, as the two
> trees stack onto each other with no separation. It would be nice if
> root commits used something other than *, and/or if they could be
> colored differently by default, or via some option to make them stand
> out as parent-less commits.
> 
> Is this feasible, or already possible?