UK company Purlfrost has a large selection of window film for many applications; Decorative, Stained, Reflective and even a kids range. My favourite would have to be their Stained Glass range that can be applied anywhere. When the sun shines on it, it would show the best colour onto the wall and ground. Great for a yoga room.
You can apply it easily yourself and they have an installation guide online. Purlfrost will happily ship worldwide, just contact them first and advise what you are intending to order.