Questions for ‘Turning jeans blue with sunlight might help the environment’
![several pieces of denim dyed different shades of blue are fanned out on top of each other](https://www.snexplores.org/wp-content/uploads/2024/04/1030_denim_dying_feat.jpg)
Denim yarn exposed to sunlight can change color, researchers noticed. They found indican can react with light to develop its iconic blue hue.
Svetlanais/iStock/Getty Images Plus