Black background tangent map

I’m sure this question has been asked a dozen times, I just cant find the answer. When I bake my tangent normal map everything works fine, but in the space between UV layouts there is black!!! It doesn’t affect the displayed image but is there any way to have a nice blue or tangent neutral color instead???

Much obliged.

unwrap

create new image, make the colour 0.5 0.5 1.0

disable ‘clear’ baking option

Thankyou, I was hoping that I could just press a button, but this is pretty easy as well.