What is O 2 rich blood called?

Well oxygenated.

It means breathing room air the person has >98% oxygen saturation. (aka blood sat)Their heart and lungs are working together and keeping the pumping the oxygen to their organs sufficiently. A person with low blood sats may have pneumonia, asthma, COPD or could be a premature new born with insufficient surfactant in their lungs to pull in the room air / oxygen.

A person with chronic oxygen poor blood may be confused, dizzy have high blood pressure, have a headache or suffer brain damage.