iPod touch 4g contrast variations

Here's the problem that I am facing:

I have a 4th generation iPod touch that I bought back in 2010 shortly after it came out. My cousin has the same iPod, except hers is a newer white one. When we compared the two side by side, the screen on mine appears to have drastically more contrast than hers. We made sure the brightness was set exactly the same, but hers looks a little brighter and the colors are more washed out, mine is a little dimmer but it has a lot more contrast and more vivid colors.

I recall that when apple released the white iPod touch, they also dropped the price. Maybe they cheaped out on the LCD in order to cut costs? Or maybe one of our iPods is defective?