Thats exactly what I was thinking. If you use both colors, but keep them seperate and distinct, you could get some really cool motteling effects.
Also...You could use clear glass to simulate water. So not only could he look like he was fresh out of the ocean, but you could also make it look like he was sitting in a puddle on the table.
Im considering taking him some LR
(painted to look like it does in the tanks) and having him put the octo on the rock. He could use the glass to make it look like water rolling down the rock...It could be really stunning.