I mean, I don't
care very much either, but Lois should have black hair.
Dennis is mostly right, although I'd like to point out that for like twenty years, Lois was drawn highly on-model. Post-Crisis, especially after about 1996 or thereabouts, less so.
They dyed Famke Jansen's hair, anyway.
At least they hired an actress who's old enough to convincingly portray a veteran reporter, though. That's arguably more important than a eumelanin count.