Screen discoloration on an iPad Pro can be caused by software glitches, hardware issues, or screen damage. First, try a forced restart by quickly pressing and releasing the Volume Up button, then the Volume Down button, and holding the Power button until the Apple logo appears. If the issue persists, check for a software update under Settings > General > Software Update. If that doesn’t resolve it, it may be a hardware issue, and visiting an Apple Store or authorized service provider is recommended.