Thank you for sharing, I’m enjoying reading it.

Dolphin paintings are for sale here:

https://www.georgiaaquarium.org/booking/dolphin-paintings/

https://marineland.net/custom-dolphin-paintings/

Wikipedia says that they “lack short wavelength sensitive visual pigments in their cone cells”, so they don’t see blue as well as we do… Which isn’t surprising really.

They could stack rocks to create a mosaic.