I didn't know a proper name for this but I have been doing it informally since I started gardening. I always have sections in my gardens where I color block. And I must do it subconsciously too because I end up with echos by chance often too. And then I have sections where I just want a big pop of many bright colors. I tend to do this more with annuals.
I'll have to go through my pics this weekend and find some good ones
