That's a helpful perspective, but hopefully you already have workarounds on the color issue. This is simply making diff pieces easier to copy / pasta -- which I for one have needed to do. Change my mind on a refactor midstream, need to restore part of the file, etc.
You might investigate the tools your editor of choice provides for working with diffs. You might be surprised at how easy it can be!
(In Emacs, if you're using git, magit is an amazing package. You can select a commit from the logs, dive into the diff for a file caused by that commit, highlight a region of the diff and revert the change in your working copy. It's wonderful.)
From the git book itself: `git config --global color.diff.meta "blue black bold"`