Hello!

I dont know if you've found the answer yet but if you wanna know;



1. Scan the drawing and save it in your pc.

2. Open the drawing in Photoshop.

3. Change it to black and white. (Under Image bar)

4. Adjust the level of the drawing to make it less messier, brighter, etc. (Under Image bar)

5. Open a new layer, set it to Overlay.

6. Paint in any colour you wanted. You can also use the Gradient tool for easy colouring of the whole canvas.

7. Play with the colourings and also the opacity of the layer.