[D-community-offtopic] minimising battery consumption - choosing screen saver/ blank screen color

[Zenaan Harkness]

I have a Lenovo x220 laptop which I use and would like to know, when
locking/blanking the screen, should I choose white, or black, as the
locked-screen color?

I want to minimise battery usage.

Of course I do not run a screen saver other than a blank screen.

Not sure if I should have posted this to debian-user sorry. Happy to
repost if that's recommended.

TIA
Zenaan