Wikipedia states: "Pastels is the mixing of pigments with chalk", and that this is the origin of the word "pastel" referring to "pale".
This is incorrect.
According to the Pastel Society of America, the word derives from the French, "Pastische", and the binder used in making the soft pastel medium is methylcellulose, (not chald), which is derived from the cellulose of vegetables.
Chalk is derived from sedimentary rock, a form of limestone composed of a mineral, calcite.
How the fabulously vibrant painting medium, which dates back to the 16th century, ever got linked with the word, "pale" I cannot guess.
"Pale" infers, weak and boring indicating an unhealthy state and gives pastels bad press.
Some of the most famous painters of the world have used soft pastels, (not to be confused with hard pastels, or oil pastels) to create magnificent works of art.
The difference between soft pastels and hard pastels, (which use more binder of a different material) is evident to anyone who studies works done in the two mediums.
Soft pastels have the look of oils, especially when used in multiple layers giving, giving them a rich texture just as oils do when layered. Pastels are simply a dry medium using pure pigment. If a binder is said to be used other then the minimal binder in pastels itself, it would be the workable fixatif sprayed between successive layers of pigment.
Pastel pigment derives from the same minerals in the earth, such as coblalt, cadmium, manganese, etc., that oil paints are made of. They are simply a dry compressed medium not requiring brushes or other tool so that they are immediate, fresh and full of life like uncooked vegetables from you garden.