Here is my one marker challenge drawing.
The way I picked my color; I counted the number of markers I had, and had my sister pick a random number. Since my markers are in a case, and in color order, she picked 29, and that was R11!

This challenge was a little easier than I thought, and I also use the colorless blender. hope you like it! I might do the no eraser challenge and the no line art challenge next.