What's your picture? To me it looks like the system takes main color from your wallpaper. I have black dog on somewhat dark carpet. But it's a wild guess👀
Discussion
It's the inverted version of the joy division unknown pleasure album cover that was originally a textbook page describing neutron star patterns
(White with black lines, I have the inverse on my other phone. I'll have to switch the backgrounds .·´¯`(>▂<)´¯`·.)