I am just coming back to Photoshop after a couple of years, I used to know why this happen, but can't figure it out now.

I have loaded up a design in my photoshop and the white area is coming up eggshell colour, I know it's not my screen drivers because if I start a new design in RGB it comes up crisp white.

I used to be able to fix this eggshell colour issue i just can't recall how i did it.

any suggestions.