ultrared

1. datednot comparableinfrared
2. not comparableOf a very intense shade of red.

   […] an ultrared pigment that lacks mercury and sulfur.

   2000, Anita Albus, The Art of Arts: Rediscovering Painting, page 318

   2 more examples

   With her chest thrust forward, her head held high, and an ultrared smile painted on her lips, she advanced toward Jeanne with outstretched hands […]

   1986, Fanny Deschamps, The King's Garden, page 180

   She’s abandoned her ultrared lipstick and nail polish and her turned-up collars and has taken up moderate pinks and going on diets, and grooming.

   1988, Margaret Atwood, Cat's Eye

plural ultrareds

1. countabledateduncountableinfrared