Why Candles Discolour and How to Keep Colours True
A batch of crisp white candles can turn cream or yellow within weeks, and brightly coloured candles sometimes fade or change shade on the shelf. Discolouration is especially frustrating for makers who sell or gift candles. The main causes are fragrance ingredients such as vanillin, exposure to light and heat, and wax quality. Understanding them helps you choose ingredients and storage conditions that keep candles looking fresh.
Vanillin and fragrance oils
Many fragrance oils contain vanillin or ethyl vanillin, which gives sweet, bakery and vanilla scents. Vanillin naturally discolours over time, turning wax yellow, tan or brown.
Fragrance suppliers often list vanillin content. Use low-vanillin fragrances for white candles, or embrace discolouration by choosing warm-toned dyes that complement the colour change.
Light and UV exposure
Sunlight and fluorescent lighting fade dyes and yellow some waxes. Candles displayed in bright windows discolour much faster.
Store candles in boxes or dark cupboards and display them away from direct sunlight. UV inhibitors added to wax can slow fading.
Heat and overheating wax
Heating wax too hot or for too long can cause yellowing. Follow wax manufacturer temperature guidelines and use a thermometer.
Avoid reheating the same wax repeatedly. Store finished candles in cool areas away from heat sources.
Wax and dye quality
Different waxes discolour differently. Some natural waxes have an off-white tone that may change over time.
Use dyes designed for candles and test colours over several weeks. Some dyes fade faster than others.
Test before production
Make test candles with each fragrance and dye combination and store them in typical conditions. Photograph them weekly to track colour changes.
Testing helps you choose combinations that stay attractive and avoid surprises after candles have been sold or gifted.
Label and set expectations
If using fragrances known to discolour, note on labels or product descriptions that natural colour changes may occur. Many customers understand this with vanilla scents.
Consistent packaging and storage practices keep your products looking their best.
Tips for white and pastel candles
White and pale pastel candles show discolouration most clearly, so they need the most careful ingredient choices. Pair them with fragrances listed as vanillin-free or very low in vanillin, such as many fresh linen, eucalyptus, citrus and floral scents, and avoid bakery or vanilla notes in white wax.
Store finished white candles in closed boxes as soon as they have cured, and rotate stock so older candles sell or get gifted first. If a few pieces do yellow, they can be relabelled as a warmer colour variant or kept for personal use rather than wasted.
Keep good batch records
Write down the wax batch, fragrance supplier and lot, dye amounts, pouring temperature and storage location for every batch. When one batch discolours and another does not, those notes usually reveal whether the cause was a new fragrance, a different wax delivery or a sunny shelf.
Supplier formulations occasionally change without much notice, so a fragrance that stayed white last year may behave differently now. Keeping a small reference candle from each production batch makes it easy to compare colour over the following months.