[Yemeth]

> and way-too-subtle shades of grey

MacOS went downhill when Jonathan Ive decided to throw out all colors in favor of the 'content'. To this day I spend too much time deciphering blue-greyish icon shapes in the Finder's side bar.

[eyelidlessness]

I may be misremembering, but I’m pretty sure the monochrome icons began well before Ive had influence on the software. OS X moved towards shape rather than color in eg iconography to support UI scaling (which had been an effort, and a more ambitious one, for years prior); and then eventually to support adaptive theming most recognizable (for its value anyway) in dark mode.