Comments:
A handy reference. If you are wanting to design a specific color, we direct you to Heath's (Updated) Colorsliders where you can use a 'color picker,' HEX code, RGB, HSL or HSB values to get that perfect color. You can also check out our SWColors Demo for a practical application of these concepts within a p5js ecosystem.
For greater detail about color modes, we direct you to Colorizer: a terrific resource.
Remembering that there are 360° in a circle, red is situated at the top of the wheel at 0°. From there, yellow-green is at 90°, cyan at 180° and blue at about 225°.