How many letters does the top answer for “of deep purplish red” have?

The most common answer is magenta (7 letters).

Crossword clue: of deep purplish red

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

magenta 7 letters wn-def

a battle in 1859 in which the French and Sardinian forces under Napoleon III defeated the Austrians under Francis Joseph

author of deep red 50% similar → argento

composer of deep red 50% similar → argento

director of deep red 50% similar → argento

wrote deep red 50% similar → argento