What Would Be A Good Cutie Mark for my OC Ocean Grey?

I would do a রামধনু colored ocean অথবা do something like the ocean slowly turning from a blueish color to a greyish from one end of a wave to the other

I would go for a few waves in the ocean. One of them is blue, and the other one is turqouise.

I suggest a রামধনু rain drop (Thats only what I think)