For this little fishy I added back and forth lines with blue ball point pen from top right corner to bottom then again from top left corner to bottom slowly and deliberately the way a fish swims. Then I tackled the tank from the yellow center to the deep purple bottom. Like light refracting through water. The bubbles are complimentary to pop and the fish reminded me of goldfish so an orange top to bottom was in order for him plus it draws your eye down to the purple corner then back over the bubbles again. Complex kiddy coloring page and great adult fun!