Interesting topic Wanda and thanks for the instructions on how to carve out a pillar. I've usually just let them burn enough to make a well to hold a real tealight then messed around with a knife but your way sounds much neater. :-) I burn real tealights, votives, tapers, then pillars in that order of frequency but tealights the most. I have a bazillion tealight holders (ys finds) and feel they are safer than tapers with the cats. I like the beeswax or soya the best altho have a lifetime supply of paraffin ones but mostly use them outdoors in the summer. Ikea has the best quality paraffin tealights for the lowest price IMO and sell in bags of 100 for about $3 on sale ($4-something regular) and I've also bot them at YS's for even less. I do have some battery ones I got a few years ago for the RV (for safety) but wasn't impressed with the appearance of the flame altho I've been told they have improved so should give them a try again. I like the idea of remote control pillars as I have the same accessibility problem on my mantel. I'd like to use them as there are convection currents because of the stove and my beeswax tapers dripped on the silk poinsettias at Christmas.

No need to "rough up" anything. Use silicone caulking to adhere the marbles to glass. I've glued those marbles to many items and grouted them and others on the Garden Junk forum have, also and that's about all you have to do. If the glass is dirty you may want to clean it well with something but that's it. Many suggest the GE Silicone II but it's up to you. I use the Mainstays cheap stuff from Wal-Mart and it works also. GL

An alternative to adding color might be to leave the candle a natural color and blend dried herbs or flowers, or beads or trinkets into the candle wax in such a way that they are visible, through the wax, at the sides of the candles, for interest.

Discoloration can be due to many reasons the additives you are using and temperatures. Preheating of molds and jars should be done for better results.