In the additive color system, or RGB color model, used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light. Cyan is the complement of red; it can be made by the removal of red from grey.
How do you make bright cyan?
Glop a small amount of turquoise-blue (cyan) paint on one side of your palette, and squeeze a bit of green paint on the other side. Alternately, squeeze the blue and green paint directly into the same glob. If you don't already have green paint, you'll need to make it.
Is cyan a primary color?
The modern primary colors are Magenta, Yellow, and, Cyan. With these three colors (and Black) you can truly mix nearly any hue.