In previous versions of macOS there was an option called "Appearance" under the System Preferences/General menu. You could set this to "Blue" or "Graphite" and it would change things like the min/max buttons to/from coloured to graphite. Under Mojave this option is missing. So, as a result, I am no longer able to change the system colors of all the buttons, regardless of whether I select the Light or Dark Modes. So, where is this option in Mojave? For example under macOS High Sierra I had set this to "Graphite" and in Mojave I can flip between Light and Dark Modes and all my buttons are still Graphite, I cannot set them back to "Blue"...
Dark Mode: Appearance Control Missing
It's the long list of colors just under the ligh/dark mode buttons.
So, the "Accent color" or the "Highlight color" changes the color of the window buttons etc?
That's right. I suppose if you used grey buttons on a dark baground, the contrast would be insufficient.