When serum bilirubin increases and secretion of urine bilirubin is out of balance,
jaundice starts to show
up. The degree of jaundice can be described from golden yellow, yellowish green, dark brown to deep dark green. This degree of change is related to the advancement of liver disease, which is also indicated when the urine turns to be dark brown, and at the same time, stools become pale and sometimes clay color.
I agree with KjFlicka; get tested for Hepatitis.