I thought nullabor was just another odd tag that didn't make sense, but no-- this is a plain in Australia! Where, get this, there aren't any trees and it's muddy brown.
For more info, see the Wikipedia post!
Also, I don't know why colins apparently is tagged for all these green-ish brown colors, but to whomever/whatever colins is, I salute you. I'm not sure why; I don't really like these colors, but you certainly do, or whatever you are is associated with it. A mystery I will forever leave unsolved.
Thank you for reading my Color of the Day reviews, everyone! This bot has provided me with no end of things to think about, even if half the time I'm just confused about the tags.
Thank you also to @effy who made this bot. I haven't seen them around in a while, but I hope they know the effort was appreciated.