From three basic colors (red, blue and yellow) and 11 main colors you can create 10 million shades on a spectrum that can be seen by the human eye. 

Emotions have a similar spectrum.

According to studies reported in Current Biology, researchers observed facial signals to identify four basic human emotions:

1. Happy;
2. Sad;
3. Afraid/surprised; and
4. Angry/disgusted.

Psychologist Robert Plutchik's Wheel of Emotions explains the emotional spectrum we feel based on personal experiences. These nuances are the emotional core of consumer decision-making.