A man (possibly the king of a realm) lives in a kingdom, its quite likely grey, and he discovers various colours in his castle / dungeon. You see a brilliant patch of colour in an otherwise totally grey scene as he discovers each colour. He rushes outside and paints the entire land colours, but this makes the inhabitants sick / depressed / angry etc. based on the characteristics expected of that color. Colors include (from memory) pink, cyan and yellow.
I first had this read to me in the late 70’s and as it was from my public library so may have been published considerably earlier, perhaps 1950’s or 1960’s.
This sounds an awful lot like Arnold Lobel’s “The Great Blueness”.
This sounds like “The Great Blueness” by Arnold Lobel. I encountered it recently in “The Arnold Lobel Treasury.” According to that book’s copyright page, it was first published between 1963 and 1974. Classic Arnold Lobel that’s still delightful today!