I've never done koi before so I had to do a goggle search to see what they looked like. I colored them in with my copics and added a few lilac crystals for bling. I didn't color the water in as the first one I did I did color it but I prefer it uncolored. It was just too blue/green.
The copics I used are as follows:
RV14, 19. 13
B09, 12, 06