How many letters does the top answer for “a roundel of a red color.” have?

The most common answer is torteau (7 letters).

Crossword clue: a roundel of a red color.

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

torteau 7 letters web-def

A roundel of a red color.

a red color. spenser. 50% similar → lastery

displaying a red color 50% similar → redly

of a strong red color. 50% similar → highred