I love this idea, too! I'm basically using this forum as my inspiration board! Ha! Share ideas here and sift back through them later.
All you need is to get a case of those clear glass votive holders (restaurant suppliers, craft stores, amazon available), a couple pastel colors that go with your color scheme, and a couple paint brushes. Swirl a little watery paint around the inside of the votive holders and let them dry. That's it! Don't swirl or fret over them too much of the colors will get muddled together!
These are great for your shower, rehearsal dinner, deck parties, etc. too!