You know, this isn't happening on my phone. I checked with a digital camera and processed the resulting picture. (thanks, higher education!) If you have screen protectors, make sure they are the same. The guy who sold me the phone included EVO Shift screen protectors and installed them for me. He specifically noted the package includes three covers, but the third is an anti-glare film with a different tint.
And you are noticing this issue when locked in tablet mode, yes?