I had diarrheal infection about 20 days back. at first it was going semisolid but now normal. but it is multicoloured half normal and half dark brown.

Bile Colors: The gall bladder located under our liver delivers a dark greenish liquid into our intestinal tract that gives stool it's color. Since you are recovering from a diarrheal infection, the digestive tract may still have healing damage that is changing the speed of the bile mixing with stool. Generally if stool is pitch black, red or white it's ok.