No there is not a requirement. Good suggestion to at least wear an orange hat/cap though.
I personally only wear an orange hat on opening day and when deer season runs. Otherwise I’m in pretty subdued colors.
Farmer once told us to get rid of our orange (not during deer season and on his private ground), he said the birds would see us better all blazed orange. So we did and well, as always, he was right. We did pretty good that afternoon. Of course, you need to be particularly cognisant of where your hunting partner(s) are when doing this.
Personally, I still prefer to have the orange cap on
I like to be pretty well covered in orange while hunting. There's alot of idiots out there. Plus having others in orange let's me easily see them while I'm swinging on a bird and focusing on it. Wear orange. That isn't going to be the reason you aren't seeing birds.