The phenomenon is caused by a regular rainbow and a sunset happening at the same time.
Sun halos, arcs and upside-down rainbows seen across England
Rainbow clouds spotted in the East for first time since 2016 - BBC
Pink rainbows seen at sunset - BBC Weather
Rare rainbow-coloured nacreous clouds seen across Yorkshire - BBC News
Sun halos, arcs and upside-down rainbows seen across England - BBC
Pink rainbows seen at sunset - BBC Weather
Rare 'Technicolor' Rainbow Sea Slug Found in England
In Pictures: Rainbow clouds captured on camera in the south
Pink rainbows seen at sunset - BBC Weather
Rare Pink Rainbows Light Skies Of South And West England
Stunning pink rainbow spotted in the skies over Bristol and beyond
Stunning pink rainbow spotted in the skies over Bristol and beyond
Ultra-rare 'rainbow clouds' light up the Arctic Circle like