How many letters does the top answer for “a deep and vivid red color” have?

The most common answer is crimson (7 letters).

Crossword clue: a deep and vivid red color

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

crimson 7 letters wn-def

a deep and vivid red color

having a deep red color. 60% similar → sultanred

a variable color averaging a vivid red 50% similar → carmine

of a vivid red to reddish-orange color 50% similar → cinnabar, vermilion, vermillion