Some photo editing software should give you the correct colour values that you can just put in there. No worries!

In previous years, it has been the case that it should work on both models of iPad Pro. This requirement was removed suggesting that it can now be run on any iPad. I would make sure it is responsive using SwiftUI or similar so it works on most models. You can test in Xcode 14 your .swiftpm file using the simulators for iPad Air and iPad Pro 12.9.

Just make sure you’re submitting .swiftpm and not .xcodeproject