You *most* probably have a defective screen or some issue with your connectors and connector cables.
I would go through the following to rule out some of the most probable causes:
- Disconnect the 2 display assembly cables, clean the connectors with a cotton swab dipped in 90%+ isopropyl alcohol. Then reseat the cables and test the phone.
- If the issue remains, re-install your old screen.
- If you don't see this anymore then the new screen is defective and that's very common. But to be on the safe side, check the 2 display cables for an abnormal crease or tear. If you see any of those, you may have damaged the screen cables during the first repair attempt.
- If the green hue appears also on your old screen, you may have damaged something on the logic board during the first screen replacement. If that's the case (although I doubt it), let us know and we'll take it from there. OR you are repeating the same installation mistake with regard to the display cables (tearing or creasing them).