What are your water parameters? Usually fish going to the top indicate ammonia or some breathing issue.
When I got my watchman last week the first few days he was swimming at the top of the water, really worried me, but after a couple days he has settled back down to the substrate in a burrow.
Fish sometimes change color under stress as well, are there any fish that could be picking on him?
180g- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18