Antonyms of adj red-orange

1 sense of red-orange

Sense 1
red-orange, reddish-orange, flame-orange -- (of orange tinged with red)

INDIRECT (VIA chromatic) -> achromatic, neutral -- (having no hue; "neutral colors like black or white")

Similarity of adj red-orange

1 sense of red-orange

Sense 1
red-orange, reddish-orange, flame-orange -- (of orange tinged with red)
       => chromatic (vs. achromatic) -- (being or having or characterized by hue)