I dont know if there is an unpainted hood, but I am pretty sure there is a carbon fiber one. I am going to assume that is not the look you are going for though
Last year, a pic was shared on here of a hood without "vents". It was surmised (since no attribution was given) that this was a once-off Korean item that somehow made it over here. Also, it was surmised that it was photo shopped. So, I can't say more.
But IF it is real, perhaps Kia would sell you one and ship it over?
I checked into Kia having a different hood available in Korea.
They said that there is no OEM that is available from them that doesn't have the vents.
Guess I'll have to buy another hood and have a body shop remove the vents.
I don't mind it being made in carbon fiber, but I want it painted in hichroma red to match the car.