“You haven’t drawn a dragon with a hoard in a while.”
So while working on this, I had a clear vision of this dragon being red. There were also more bits and frills, but those got taken off for some reason, and I did fret a bit about how it seemed less dragony without them.
Point is, I was so wrapped up in the need for redness that I grabbed some color pencils and started layering on red pigment, muddying up the graphite lines to the point that it was mostly an indecipherable blob. In hindsight, I should have tried to render with the color pencil instead of just filling in, especially when I realized that it wasn’t quite the red I wanted at first- making it darker got it closer, but at the expense of making it look, well bad.
The gem ended up being green more for contrast than anything else.