I gave it a nice green overlay just for today. 🙂
 I drew this today in the time slot we normally have assembly in. Today assembly was canceled so I had a nice long time (1 hour 10 mins) to draw in. I think this one turned out pretty cool (do you like that 4-leaf clover I threw in there? 😉 ).
After I put that green overlay on I had a brilliant idea. The overlay is just a
photoshop layer over the top filled magic green, and then put on 10%
transperancy.
So my idea was, what if I just selected bits of the picture and coloured them
differently? I could make a nice hint of colour to an otherwise black and
white picture.
So I did. Here is my result.  I thought it looked pretty neat. 🙂