I bought a Lumia 1020 and already have a 920. I bought the 1020 for the camera, but I've found the screen is not as precisely colored as the 920. I noticed in the Lumia display+touch offers the ability to adjust the temperature and the saturation, but not the tint. The tint on the AMOLED screen is definitely greener than on the 920 and ends up looking a little like one of the cheaper Samsung devices.
This could be easily fixed by adding a Tint slider to the display+touch app in settings.
Thoughts? This is bad enough for me to want to return the phone and just wait for the software to come out for my 920.
Unfortunately, AMOLED screens are prone to some sort of tint or other and that is just the nature of AMOLED screens. I've seen some on other devices with yellow, blue and pink tints. The tint on your 1020 will be more noticable when you compare its screen to that of your 920's LCD.
If the green tint is pronounced enough to be unbearable then you always have the option of taking it back to the store you got it from for a replacement.