ipython/ipython — pull request #4608 by Carreau (2013-11-26 21:17:46+00:00)
Title: transparent background match ... all colors

I think it make sens; this is `white` with `alpha=0` so it should fail gracefully on things that don't like alpha. it's much nicer on blog post with custom themes, and not-white-but-almost backgrounds.

It changes nothing on notebook and qtconsole with default theme.

Do anyone see any case where the figure would be on a super-dark background ?