Screen tint is yellowish
I have an iPad 2 with beautiful screen. Bought my husband one and had them side by side the other day and noticed that his seemed very yellow on the exact same app. It was pretty significant. I called Apple and they said to get a replacement. We did and the second one is exactly the same. What's up with that? We are going to bring mine for the next replacement so they can see the difference in the store. We now wasted 2 expensive screen savers too!
Apple have two different suppliers for the LCD screen used in the iPad. It's possible that your two iPads have screens from the two different manufacturers.
My iPad 2 is yellowish, and so is my husband's iPad 1. My iPad 1's screen is white. I'm fine with the difference, but there is a difference.
I like to use my yellowish one at night, because it lets the screen go much dimmer than the whiter one.
My 2 is more to the yellow side than my bosses which is more bluish.
Neither one is particularly color accurate (I wouldn't use either screen to edit a Photoshop image).
I kind of prefer mine as it is easier on the eyes when I use the Kindle reader. I don't do that often as I have two real Kindles, but when I do the screen that is more to the yellow side more closely matches the real Kindle screen.