How many letters does the top answer for “author of paper towns” have?

The most common answer is green (5 letters).

Crossword clue: author of paper towns

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

green 5 letters wd-fact-v3

green color or pigment; resembling the color of growing grass

author of federalist papers 50% similar → hamilton, madison

author of the pickwick papers 50% similar → dickens

wrote paper towns 50% similar → green