This results in cyanosis in the lower extremities, a blue or purple discoloration of the skin; that's the result of deoxygenated blood mixing with oxygenated blood.
What we don't have is any deoxygenated blood escaping into the systemic circulation and causing a baby to appear cyanotic, so we call this acyanotic, which means " not blue" .
When deoxygenated blood mixes into the systemic circulation, it'll often present as cyanosis, a bluish-purple discoloration of the skin, which can be seen in a baby within the first days after birth.
The increased CO2 levels in the blood can get so bad that some people develop cyanosis, which is a blue discoloration of the skin, and this is why patients with chronic bronchitis are sometimes referred to as blue bloaters.