How many letters does the top answer for “mark with spots or blotches of different color or shades of color as if stained” have?

The most common answer is blotch (6 letters).

Crossword clue: mark with spots or blotches of different color or shades of color as if stained

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

blotch 6 letters wn-def

an irregularly shaped spot

mottle 6 letters wn-def

mark with spots or blotches of different color or shades of color as if stained