Teal is the name of a fowl (bird), but the blue teal was one of the feather colors on the (rare) blue teal. In the late 19th century, as people would buy feathers for hats, teal (or sarcelle bleu in French) became the color of the prized feather, which would even be counterfeited. When people stopped killing birds for feathers, the fashion industry introduced the color as a dye.

Tiffany Blue is a branded and trademarked color of the luxury brand Tiffany & Company. The color is described as a "robin's egg blue". Used prominently on their boxes and bags, it is one of the considered one of most recognizable luxury brand colors, at least in the United States.

Turkey is named after the color near their eyes or on their plumage, which reminded them of the color turquoise (or turkeis, as 16th century English called both the stone and the bird). In French, the bird was also called "Coq d'Inde", not to reflect an Indian heritage for the bird, but rather because inde was a shade of blue in French.

Turquoise is the name of a precious stone, which can range in color (and even change colors) from a blue to a green. It was a highly prized stone found in Ancient Egypt, Persia/Iran, and the American Southwest. It is not related to the country Turkey, and there are 13th century sources which use the name, which would have predated any purported Turkish turquoise trade.

Turchino is an Italian word for the color of the sea or sky, which is also connected to the word turquoise. There are early similar cognates in Judeo-Aramaic and Hebrew - such as tarkia and rakia, which both relate to the sky and the color of a stone.

Cyan is the name of the color used in printing (CMYK). One type of early photography were called cyanotypes. The name comes from Ancient Greek, but can even be found prior to that in various Ancient Near Eastern languages. It is unclear exactly what the original word was related to -- if a stone, a flower, a bird, or something else.

Glaucus is an ancient Greek word for the color blue-green, like the color of the sea or eyes. There was even a Greek myth about a god named Glaucus, who was a fisherman who ate a magic herb, and transformed into an immortal fish-man-god, with a very colorful social life.

By the 17th century, we can find that both French and Spanish took the word glaucus and turned it into the word garçon (or gars) which referred to a blue-eyed boy or unmarried young man, with the connotation of one who misbehaves and was quite a "player". In fact, some theorized that the French bleu came from there.

Many incorrectly think the Greeks (or Homer) couldn't see the color blue and thought the ocean was red because of a mistranslation of the phrase "wine-eyed sea". Not only did the word mean "hazy" as it referred to drunk sailors, and the gleaming (with a word related to glaucus ) Athena brightly showing them the way, but there is another problem with the incorrect reading. The Greeks didn't drink red wine.

In fact, considering the sea to be the color blue is a rather modern idea. Shakespeare considered Neptune (the god of the sea) to have a green cape.