It is the bile that gives color to our feces and urine. insufficient bileIt means that the bile is not being squirted onto your faeces which gives it the brown pigment, so it could means that something such as stones are blocking the bile passage
Newborn feces are actually called meconium, and they look like black tar, sometimes with a slight dark olive green or yellow tinge. After the first few days of passing meconium and drinking milk, feces usually turn to a light yellow color.
The healthy feces are usually 3 centimeter in diameter, golden yellow or brown in color, soft but not too soft like a mud.Reference: http://wiki.answers.com/Q/What_is_yellow_on_toilet_paper_after_a_bowel_movement_my_feces_are_still_medium_brown&action=edit§ion=new
Indigo carmine turns yellow in an acidic environment due to a change in the pH of the solution. In acidic conditions, the color of indigo carmine shifts from blue to yellow. Adding an acid causes the pH to decrease, leading to the color change.
Gold appears yellow in color due to its unique electronic structure. The electrons in gold atoms absorb and reflect light in a way that causes them to appear yellow to the human eye.
When you mix lemon juice with bromothymol blue (BTB) solution, the color will change from blue to yellow. This is because the acidity of the lemon juice causes the BTB indicator to shift to its yellow color.
If your feces is yellow, I would suggest seeing a doctor.
Black
No, feces can vary in color depending on factors such as diet, hydration, and presence of medical conditions. While brown is the most common color due to the breakdown of bile by bacteria in the digestive system, colors like green, yellow, or even red can occur in certain situations.
Green stools are generally caused by eating dark-colored foods and especially drinks. So if you enjoy drinking purple and blue drinks, your feces may be green instead of the usual brown color. The reason it becomes green is because bile is yellow, and yellow and blue make green.
Carotenoids are the pigments responsible for the yellow color of leaves in autumn. These pigments are present in the chloroplasts of plant cells and help in the process of photosynthesis. As the green chlorophyll pigment breaks down in the fall, the carotenoids are revealed, resulting in the yellow hues in leaves.
Penguin feces can range in color from white to green, depending on their diet. The green color comes from their consumption of krill and fish, which contain pigments that can give the feces a greenish hue.