Natural colors fade due to several environmental factors that cause chemical changes in pigment molecules. The main causes include:
- UV radiation breaking down chemical bonds
- Oxidation from exposure to air
- Chemical reactions with environmental pollutants
- Temperature and humidity fluctuations
Different pigments have varying levels of lightfastness (resistance to fading). For instance, carotenoids are particularly susceptible to oxidation, which is why carrots lose their bright orange color when exposed to air. Similarly, chlorophyll breaks down quickly when exposed to heat and light, causing green vegetables to become yellowish. Natural textile dyes often require special care and storage conditions to maintain their vibrancy longer.