Somewhat related - I feel like we're in the middle of a general trend of boring, monochrome design.
Car colors come to mind:
https://www.thedrive.com/news/37001/this-graph-shows-how-car...
Winter is coming - that means a sea of black, dark blue, or dark brown winter coats everywhere.
Or the trends towards same-looking logos that have been discussed here before:
https://news.ycombinator.com/item?id=32040506
I guess all trends are cyclical, so looking forward to an explosion in colour in another 5-10 years!