So basically each yoshi represents an aspect of the that makes up the bodily quintessence. People of learning discovered that every yoshi is either HOT or COLD, and WET or DRY. and this allowed the yoshis to be organized based on their temperament.
Theophrastus, the red yoshit is HOT and WET so his temperment is SANGUINE.
Ascelepius, the yellow Yoshi is HOT and DRY so it can be CHOLERIC.
Melquiades, the blue Yoshi, I'd known for being COLD and DRY and MELANCHOLIC.
And finally the freen Yoshi name of Zosimos is COLD and WET and this of PHLEGMATIC
It's okay if you understand