Why different colors with each system?

Four Greek Humors 400 BC

William Marston DISC 1928

Don Lowry True Colors 1978

Marc Acetta

Taylor Hartman Color Code 1987

Smalley & Trent Animal Personality Test

Beaver – Gold/Responsible/Guardian
Fox – Orange/Adventurous/Artisan
Dolphin – Blue/Harmonious/Idealist
Owl – Green/Curious/Rational

In Please Understand Me (Prometheus Nemesis, 1998) Keirsey further develops  his own typology of the four basic “temperaments,” which he calls, after Plato’s categories, Artisans (The Fox), Guardians (The Beaver), Idealists (The Dolphin), and Rationals (The Owl). He discusses forms of intelligence, social roles, self-image, values, and interests of each temperament. His book includes the original MBTI-like test and a new one for his four temperaments. It also has chapters on Mating, Parenting, and Leading according to the different temperaments.

Paracelsus