Yes, you can mix acrylic and watercolor paint since they are both water-based. You can experiment to create different shades of color and textures depending on the ratio you choose to combine them. Be aware that once you mix acrylic and watercolor paint, in terms of drying, the mix assumes the property of acrylic paint. This means that unlike watercolor alone, you cannot revive colors once dried. Asides from mixing the two paints, you can use both in a painting with either one acting as the background.