The rainbow was spotted outside Land Rover BAR base in Portsmouth – meaning those within two miles were in with a shout of claiming the prize.
Viewers are invited to look out of their windows to see if they can see the illuminations as part of the competition.
The prize is part of a live segment of the hit ITV show led by singer Fleur East, who arrives at secret locations and fires a rainbow of colourful spotlights into the sky.
The lucky winners – who were supposed to be getting married today – said they were ‘over the moon’ after receiving the prize.