When I went to high school (decades ago) the pencil crayons were made mostly of ‘filler’. Now there are high-quality, pure color products available. They can be purchased in the following forms:

Wax based

Oil based

Pastel

Water soluble

There are many companies producing high-grade pencil crayons. Here is a list of some of them.

Prismacolor Artstix, woodless version, (wax-based)

Prismacolor Lightfast (wax-based) Developed in compliance with national standards for colored pencil lightfastnes.

Prismacolor Verithin, hard version of wax-based Prismacolor Premier

Faber-Castell Polychromos (oil-based)

Lyra Rembrandt Polycolor (oil-based)

Derwent Artists (wax-based)

Derwent Coloursoft (wax-based)

Caran d'Ache Luminance (wax-based) Developed in compliance with national standards for colored pencil lightfastnes.

Talents Van Gogh (wax-based)

Packages of these color pencils range from $42 to $200 depending on the number of pencils in each set. Some companies' pencils come in a package or tin box of 32 color pencils or 48 color pencils. Other sets contain 72, 120 or 132 pencils.

Due to the pureness of the pigment, an artist can create their secondary, tertiary and complimentary colors by fusing or layering. Therefore, it isn't necessary to purchase the biggest or most expensive box of color pencils -- but like a quilt-maker with her hoards of fabric -- it sure is fun to have them.