Whether you add color to your candles or leave them dye-free, they will be affected by natural and/or artificial light at some point. Like the way sunlight will turn white fabrics yellow or cause bright colors to fade, dye-free candles will start to yellow and dyed wax will eventually fade. Fragrances with a high vanillin content and many citrus scents can cause the wax to develop a yellow tint within 24 hours. Fragrances with small amounts of vanillin and floral scents can cause a gradual yellowing over time.
Use a candle UV inhibitor
Sunlight will cause dyed candles to fade. A UV inhibitor acts like a sunscreen for your candle, blocking the UV light to prevent fading and yellowing. It is important to note that a candle yellowing due to the vanillin content in the fragrance oil is a separate issue and will not be prevented by the UV inhibitor.
Add a small amount of white dye
If your candle is yellowing due to vanillin in the fragrance oil, use a small amount of white dye to help counteract the yellow tint to give you a more natural, uniform soy color.
Minimize your use of vanillin containing fragrances
Vanillin is known to cause discoloration in wax. If you are finding that the UV inhibitor or ivory dyes aren’t working to your liking, or if you don’t like adding them to your workflow, consider minimizing your use of fragrance oils containing vanillin.
