Glow in the Dark Materials that Shine in Full Colors.

Scientists have developed glow-in-the-dark materials that shine in colors!

Phosphorescent materials absorb energy when exposed to light and emit that energy as light again over long time periods.

Good blue and green phosphorescent compounds have been around for some time but until now red ones lasted minutes instead of hours. Saito and colleagues Naoki Adachi and Hiroyasu Kondo got around this by adding red dye to green and blue phosphors.

http://www.newscientisttech.com/article/dn11372-fullcolour-glowinthedark-materials-unveiled.html