JoAnn has some really bright battery power rice light sets in different colors. 25 lights per strand and the purple is a nice dark purple. First set I have come across that was bright enough to see in daylight and still have a deep color. All the light sets have a test button so you can see what they look like in store.
Great costume potential with these sets. A black tulle veil draped over the lights would give them a soft glow. The second photo was taken on a cloudy afternoon indoors. You can find this set here on the JoAnn web site.