diaprer

A rare, poetic literary verb: to variegate or mottle something with different colors, as light through stained glass or flowers in a meadow. Almost exclusively found in descriptive literary prose and poetry, never in speech.

• Le soleil couchant diaprait les nuages de rose et d'or. — The setting sun tinged the clouds with pink and gold.
• Un pré diapré de fleurs sauvages s'étendait devant nous. — A meadow dappled with wildflowers stretched before us.
• Les vitraux diapraient le sol de l'église. — The stained-glass windows dappled the church floor with color.

This is a literary word most learners will only ever meet while reading, typically as the adjective diapré(e) — there's no genuine 'common mistake' to flag since almost no one tries to produce it actively.