Two to four hours after a subarachnoid hemorrhage, the supernatant of a CSF sample will be pale pink to pale orange.

The source of this color is oxyhemoglobin from lysed red cells present in the CSF before the puncture. Xanthochromia from the lysed red cells reaches its peak 24 - 36 hours after the hemorrhage and gradually disappears after four to eight days.

In the same type of hemorrhage, after 12 hours yellow xanthochromia begins to appear due to the presence of bilirubin. The bilirubin is the breakdown product of oxyhemoglobin from the original lysed red cells.

The yellow color in the supernatant reaches its peak in about two to four days and disappears after two to four weeks.