How to get rid of ESC[ characters when using git diff on Mac OS X Mavericks?

This works:

git config --global core.pager "less -r"

Do you have a LESS environment variable set? You can check using:

env | grep LESS

or:

echo $LESS

If so, you want to make sure the R option is in there. That allows the ANSI escape sequences to pass through unscathed, and they'll be rendered as colors in the terminal.

Just for reference, I use this:

export LESS=eFRX