PS4 Image Color Noise Caused by Scaling or RGB Full Limited?

What would cause image color noise in PS4 games so that pixels will have slightly different colors when you take screenshots with a capture card?

I have the same game on PS4 and Xbox 360.

On Xbox with the resolution set at 720p, I could take screenshots of the same game menu screen and the pixel colors of images and text will always be the same.

On PS4 with the game set to 720p, I get slight color variation on some pixels like noise when I take a screenshot of a menu, navigate to a submenu, load something and return back to the menu. I can see the noise pixel variation in images and text by layering the screenshots in Paint.NET and setting the top layer to Xor.

Also, UI on the Xbox have solid color lines and on PS4 the UI lines are blended with neighboring pixels as if it was scaled.

What would cause this difference on PS4? Is the game at a different native resolution on the PS4, so running at 720p scaling the game down? I tried switching to 1080p and the lines are blended. Does RGB range set to Limited or Full cause this?

Submitted by ps4_video Xbox 720 Release Date 2015