Cartoon, maroon, and dragoon are all examples of this common suffix. The "oons" came about between 1500 and 1700, when new English words were created from French and Italian ones that ended in "-on" or "-one."
Carton, the French word for cardboard, was the inspiration for "cartoon" only because the sprightly drawings were originally sketched on such material. At the same time "cartoon" began to refer to a drawing in English, the French extended the original word's meaning to a container made of cardboard. That's how we got the milk carton.
Marron (French) is a chestnut that's reddish-brown in color. So by extension, its name became the basis for the color "maroon" in English.
In 1622, a dragoon was a mounted soldier armed with a short, heavy musket or blunderbuss that spouted fire like the mythical dragon.
Someone who has very fixed ideas about something is often called "dyed in the wool."
Why? In the Middle Ages, when a piece of woolen cloth was dyed, the color was rarely uniform. Dyed clothing tended to be blotchy and uneven. After it had been washed a few times, the color would be even more mottled.
Then it was discovered that dyeing "in the wool," that is, dyeing the wool before it was spun into thread and woven into cloth, yielded a much more permanent and evenly fixed color.
SOURCES: 'The Barnhart Dictionary of Etymology,' by Robert Barnhart; 'Morris Dictionary of Word and Phrase Origins,' by W. and M. Morris, 'A Hog on Ice,' by Charles Funk.