The best way to get water-based paint out of clothing is by scrubbing the paint with a mixture of dish soap and water. Rubbing alcohol may also help remove more stubborn paint from clothing.
Typically, wet paint is much easier to remove from clothing than dried paint. If paint is still wet on a garment, blot it with a clean cloth and rinse the paint spot under running water. Blot the area once more to soak up any excess paint. Gently scrub the area with equal parts dish soap and warm water. Rinse the area once more and blot it dry. Dried-on paint is often too difficult to remove. However, blotting the area with rubbing alcohol may help loosen the paint. After using rubbing alcohol, rinse the garment and try gently washing the area with mild detergent and water.