Candles represent the element of fire. Candles are a important part of many spells or prayers. Diffrent color and scents call down diffrent aspects of a spell. Here is a quick color reference you can try.

Red	Red represents fire, strength, fertility, love.
Yellow	Yellow represents doing things, good luck at work, and fairness.
Blue	Blue represents loyalty, friendship, truthfullness.
Green	Green represents money, growth, spring, and good luck.
White	White represents purity, blessings, and family.
Black	Black represents banishing of evil, finishing things, stability.
Purple	Purple represents gifts, surprizes, royalty.
Brown	Brown represents the home, fruitfullness, protection.