This is a digital colorization of this amazing sketch by ~twinkleturtle
(Check out her gallery!):
All credit for the sketch and idea goes to her. And this was done with permission.
(I also used a stock image, but I can't even see it in the final image)
I made a couple minor alterations, but mostly kept the sketch as it was.
The original sketch (And by extension this colorization) was inspired by this