This variation give me the idea to play around with my new tube of Transparent Oxide Orange (Rembrandt) and to see what it could do. My conclusion was that it produces the most delicious, luminous orange whilst also behaving beautifully even alongside challenging colours like blue or black. I had no problems with accidentally mixing a bilious green in this painting.
Here is a progress shot
The horns were modelled using trial and error and a great number of cotton buds (Q-tips). I removed as much paint as I put on until I got the impression of their hard, knobbly texture. This was where I was grateful for having toned the board before I started.