From Longman Dictionary of Contemporary EnglishDay-GloDay-Glo /ˈdeɪɡləʊ $ -ɡloʊ/ adjective trademark CChaving a very bright orange, green, yellow, or pink colour Day-Glo orange posters
Examples from the Corpus
Day-Glo• Outside the club, a woman was handing out day-glo green fliers.• Dickie was dressed in a Day-Glo orange vest, jeans and running shoes.• a Day-Glo orange vest 