I got some xmas bulbs from ts once (in with something I wanted) & they had fake snow on them in places so I put them in soapy water & ended up with clear bulbs. Didn't know what to do with them so I threw them out. Now that I paint I know that 1 thing you can do is swirl a little paint around on inside of them,take the silver or gold top off 1st & swirl 2-3 colors around. If you can do tole or other painting you could paint outside. I painted sea shells with FolkArt metallic paint with a small brush & when dry coated whole thing with DecoArt crystal clear Twinkles which is a superfine glitter/shimmer & it would be beautiful on old bulbs. I would paint the bulb like it was an orange, top(stem to bottom around it like you were painting each section of an orange.)I let mine dry overnight & then painted on the glitter. All supplies are available at Joanne's or Michael's etc. The sea shells look terrific with the tree lights. Very simple to do also.