I think his abilities are overestimated.

He has expert knowledge.

He is studying computer science at a specialized school.

He couldn't say anything about issues outside of his field of expertise.

There are many different specialty stores in this town.

He is a specialist fool, with no interest in anything outside his field.

In the old days, people used to draw water directly from the river and drink it.

The water-colored dress suits you very well.

Mizu is my best friend.

The light blue dress suits you very well.