My brother laser seems to eat colour toner when it's only printing black and white for some reason. Don't get me wrong, it's still a decent printer, but short

My brother laser seems to eat colour toner when it's only printing black and white for some reason. Don't get me wrong, it's still a decent printer, but short of what I would consider "really good". Also, I read here in another thread that a recent firmware update also blocked third party cartridges.