Looks like water to me.
I'm gonna go and get some lakefront property on TItan, set up a bait shop, rent tackle and paddle boats ....
Oh wait -- false color?
There was a sci-fi story quite a while ago about some anglers who took their fishing gear everywhere, every moon and planet, dropped a hook into every body of water just to see what if anything they might bring up. Could be something swimming around in that liquid methane lake.