The helmet and the green glow has been a problem mentioned in every report to Congress since 2012.The DOD DOTE report in 2016 identified the issue as a “Category 1” deficiency, affecting the safety of flight.
The USN and Marine Corps have started replacing the Mk 3 helmet with OLED helmets with 62 sets already delivered. Another 62 are expected in May 2022.
At present the USAF have not bought any, not aware about the UK.