And I agree about the orange Spirals being harder to find. I just saw one on eBay where the clear base glass lit up under a black light. Can't wait to get home and try this one.
I really like the base on the yellow. It's a moss agate/moonie type base with just a touch of blue in it, giving it an almost smokey look. I have an Orange one like it at the house, I'm going to try a comparison photo later.
If someone knows a specific name for that base, I'd love to know it