I've also heard that it has something to do with oxidation, and the FO's, but I have no idea about that. As I mentioned in my earlier post, I had made some candles with 1343, 3 tbsp/pp stearic, 1/2tsp vybar, ivory dye chip and 1oz/pp FO (Nag Champa). The round one was wicked with an Eco 8, and the ball with a LX18. When I burn the candle, the melt pool gets darker, and sets up as a really dark green. I had made two of each type, and changed out the wicks to flat ply, and the problem went away...... I figured it was the Eco wicks. I tried to burn another candle the other day with an Eco wick, and experienced the same problem. This time the candle was light blue, and the melt pool turned yellowish-green. Another candle that I made the same day, but light green, and wicked with the flat ply, did not exhibit the dark melt pool..... I'm befuzzled