Use Crayola. These are the best and have the best color saturation. Use a paper that will grip the color evenly. I like Stonehenge or illustration board. Have a good hand_held sharpener handy. Always try to keep a point on the crayon. This makes it go on more evenly. Apply the crayon in a professional manner. Just like you would any other fine art tool, use control and be deliberate. Don't become five years old again!
Colored Pencil Tinting . Embroider the design as desired. Tinting with colored pencil is similar to working with crayons. The result is much softer and it works well for blending color. The color is less colorfast than other tinting methods, so reserve this technique for embroidered items that won't be washed.