There is already a dark theme you know?(It's bugged but I never had problem with it).
Kureha says it's bugged, but I'm not so sure. I haven't heard of anyone actually running into issues with it recently, so that might have actually been an issue with SMF.
And Jordy, not sure if you've noticed this, but a lot of the default images that K1 uses (the small icons and stuff) have white artifacts in some spots. On the DarkModern theme, it uses a different image set that doesn't have those artifacts, but they're very visible when using yours on a smaller screen.