What gives the stool it is brown normal coulur and what gives the urine it is normal light yellwish coulur?

For urine, urobilin.: Here i will handle the question about urine. Urobilins are usually responsible for the yellow color to the urine. It is a breakdown product of billirubin, which is formed in the disposal of heme from old red blood cells. Hydration will dilute these compounds, and the urine will appear more colorless. Ingested foods dyes, medications, & vitamins can cause a deep yellow color as well.

Bilirubin: Hemoglobin from worn out red blood cells breaks down into bilirubin which is converted further to urobilins which turn urine yellow and stercobilins which produce the brown color in stool.