But it's not.
I want to teach you how to make great candles, so I'm going to tell you...no!
The reason is really pretty simple. Crayons are colored with pigments. Pigments appear to change an object or substance's color by reflecting or absorbing different wavelengths of light. But the pigments don't dissolve in the wax, they're just dispersed...floating around, basically. As the wax melts, and is carried through the wick to the flame, the pigments clog the wick. Think of it like dirty deposits in your gasoline. They clog up your fuel line. That's what happens with pigments. The pigments that don't clog the wick tend to settle and/or concentrate at the bottom of the melted wax.
The best solution for coloring wax is dye. The dye actually does dissolve into the wax and won't clog the wick.
I have done some experiments with infusing wax with natural colors. The reason that they worked was that the color dissolved into the wax like a dye (see the candle colored with annatto. Some of the other colors, like spirulina or peppermint, would have been darker if I had ground up the herbs into a powder and just dispersed them into the candle wax...but it would have acted like a pigment and either clogged the wick, or settled to the bottom...or both.
Now, before you throw away all of those candle odds and ends you've been saving, you can "overdip" your candles into the pigment-colored wax. Basically make your candles as you would normally, and then dip them (several times) into the melted, colored wax. (Obviously this only works on tapers, pillars or votives.) The colored wax stays on the outside of the candle, and not too much of it makes it to the wick.
Or, like I recommended, just use a dye specifically made for candles. They come in liquid and "chip" form and are really inexpensive.