You end up with a marble-like appearance, very cool:
Buy clear glass ornaments at the craft store, some plain old acrylic craft paints--some solid and some metallics.
Drip your favorite colors into the ornament and rotate it around slowly. When the inside of the orb is completely coated, place it (hole downward) onto the rim of a glass so that the excess can drip out for some time, otherwise it'll be Easter before it dries.
Mostly we did reds and gold & green and white. Did a few for gifts that are very lovely with dk blue, sky blue, green and white--they look like a globe of Earth, really fabulous.
Caution: the glass is pretty fragile, one shattered in my hands, that was a real treat-kids be careful. ANyhoo, my husband and I did this last evening and listened to Xmas songs, very festive and fun.