Looking at a screen constantly can put a lot of stress on your eyes, especially if you are color blind. Use the iOS color filters and this can easily be fixed!
Simply go to Settings > General > Accessibility > Display > Accommodations > Color Filters. You can choose grayscale red/green, green/red, or blue/yellow. In addition to the filters, you can also add color tints, different hues, and try out different intensities.