so does dark mode only affect the color of the dock and menubar?
I thought we found images and code baked into the system that would make everything dark...
Yeah — back in DP1, before we even had the ability to enable dark mode via the Terminal, people were renaming resource files from the dark theme so they'd be activated under the graphite theme. It looks like Apple was experimenting with making windows dark, including the titlebar, drop downs, the Finder background, etc.
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But remember, at WWDC, Apple purposely previewed dark mode in a screenshot that had no open windows — just the dock and menubar visible. They haven't really committed themselves to anything. Dark mode may or may not become a truly system-wide theme as time goes on. Right now, it doesn't make a heck of a lot of sense to touch anything but the menubar and dock, because a lot of UI components, even in the light theme, are still being heavily tweaked.