High Key or Low Key

Hi Everybody,
Ellie and me had a big argument over whether the attached image was high
key or low key. (We were just looking for a fight. I don't even remember
what I said it was.)
I might add that it has a lot more color than a typical high key or
low key shot. Why do they all border on monochrome. Why can't there be
colorful high and low key shots.
Phil
PS: You can test the dynamic range of your eyes at the low end with this
image. My right eye discerns individual steps all the way to the top. My
left eye only makes out distinct bottom steps.