That is really almost an impossible call to make until the tank is running. Whatever color you pick, short of black or white, is not going to look the same color when the aquarium lighting is running.
I wish I had an original sample of the color when I picked it, but the color on paper vs the color once painted on an aquarium and put under different lighting had very different looks. The color I picked was called "Deep Ocean Blue" when I bought it, and it looked a deep blue w/ touch of green but when placed under a 10k light it looked completely different, and using a different ballast also changed the color significantly, still using the same bulb.
I understand this is for your wall, not the aquarium, but I still think the color you see on the sample sheet vs what the actual color will look like once the aquarium lighting is running the in room is going to be a lot different.
Just look at the background colors, pay no attention to the tank. Same bulb, different ballast, same color background.
No water/light, just room light. Wish I had a better pic.
10k @ 250w
10k @ 375w