All i see is colour in that. What started off the issue. Was it an update or something downloaded? If you go into settings Accessibility Vision enhancements Is colour correction turned off and colour inversion turned off?
Did phone restart, colour restored briefly then back to black as Amy sang. BUT, smartwatch may be at fault, kept stating Sleep mode, so think is culprit. Turn off,colour restored. Thank you for your help tho 😊🙏