Jaundice can be caused by
1. Increased breakdown of RBC, which leads to, increased production of bilirubin.
2. Liver failure that can lead to malabsorption of bilirubin from the blood.
3. Blockage of biliary canaliculi leading to the backflow of bilirubin into the bloodstream.
So you can see that in all of the cases above, there is an excess of bilirubin, which is yellow in color and thus the yellow coloration of the skin and mucous membranes.