I have a real Knee-slapper for you today. I love cards with humor.
This card is a little challenging. I broke family groups and blended colors together that we don't normally do. If this is your first time trying this. I suggest practicing on a scrap piece of paper. Just draw an oval and try to mimic the look. You can also adjust the colors to your liking. You could just make a blue fish and pink fish, if you wanted to make this simple. It took some time playing around with this, but I think the end was worth it.
Blue: B00, B000
Blue Fish: B01, YG03, YG01, Y13, Y11
Pink Fish: RV14 (tiny bit), RV13, RV11, Y13, Y11 (orange YR12, YR14)
Seaweed: YG06, YG03
Sand: E31, E33