The color of the edge screen may appear green and red

The colors on the curved screen may look different depending on your viewing position.  

Due to the inclined curved surface of the Galaxy Series (S9/S9+, Note8, S8/S8+) edge screen, a green tint in color or even a blue, yellow or red tint can be observed. This is due to a phenomenon known as WAD (White Angular Dependency). 

For an AMOLED display, the WAD phenomenon results in the white color sometimes appear to be in different colors when viewing at an angle. But when viewing directly from the front or side, the color will be as expected.

White Angular Dependency Phenomenon