The coloring on this card was done with the chalkboard technique. The tutorial for this can be found here.
Some things to note: You definitely want a solid image. Your chalk is sticking to the ink. An image that is an outline will be impossible to color on dark cardstock. Also, I did wait for my ink to dry. It seemed to be smearing when I started applying the chalk while the ink was wet.
The stamp used here is by Inkadinkado.
Here's a close up of the image.