How Do Colored Flames Work on Wax Candles?

[Zenparticle]

I purchased a set of "ColorFlame" candles, they burn like a normal candle except the flame gives off colorful flame, some green, some red, some purple and orange. I was curious as to how the candle burns a different color flame? And if it would be reasonably easy to do as a project at home? I figured someone here must know how it works. Thanks.

 

[Borek]

http://en.wikipedia.org/wiki/Colored_fire

 

[Zenparticle]

http://en.wikipedia.org/wiki/Colored_fire

Perfect, thank you.