Turquoise and Aqua World

Cyan is a greenish-blue color. On the color wheels of the RGB and CMYK color models, it is located midway between blue and green, making it the complementary color of red.

"Aquamarine is a color that is a bluish tint of cerulean toned toward cyan. It is named after the mineral aquamarine, a gemstone mainly found in granite rocks. The first recorded use of aquamarine as a color name in English was in 1598."

"Aqua is a greenish blue color, a variation of the color cyan... In the HSV color wheel aqua is precisely halfway between green and blue."

Cobalt Blue
_a strong greenish blue found in; deep blue sea, navy uniforms, fashion

"Cerulean, also spelled caerulean, is a color term that may be applied to certain colors with the hue ranging roughly between blue and cyan, overlapping with both. It also largely overlaps with azure and sky blue, although cerulean is dimmer."

Ultramarine is a deep blue color and a pigment which was originally made by grinding lapis lazuli into a powder. The name comes from the Latin ultramarinus, literally "beyond the sea", because the pigment was imported into Europe from mines in Afghanistan by Italian traders during the 14th and 15th centuries."

"Turquoise is the name of a greenish blue color, based on the gem of the same name. The word turquoise comes from the French for Turkish, as the gem was originally imported from Turkey. The first recorded use of turquoise as a color name in English was in 1573."

en.wikipedia.org