What Is Normal Bowel Movement Color?

Color of normal bowel movement in most people is any shade of brown, including the light brown (described as yellow by some, but this is  not the same as bright yellow).

The following stool colors may be also normal, if they result from ingested substances:

• Green stool may result from ingesting large amount of leafy vegetables, artificially-colored drinks, black licorice, iron or vitamin supplements. Other causes of green bovel movement.
• Black stool may be from blackberries, blueberries, iron in red meat, spinach, or iron supplements, or Pepto-Bismol. Other causes of black bowel movement. 
• Red stool may be from beets, artificial colors in drinks, sweets, or ice creams, red gelatin, tomato juice or soup. When not sure, blood in the stool has to be considered.
• Orange stool may be from vitamin A, antacids, artificial colors, butter-fish, carrots, sweet potatoes, kale, spinach, turnip greens, winter squash, collard greens, cilantro, fresh thyme.   

Bile, as excreted from the liver into duodenum, is green due to contained bilirubin. Normal intestinal bacteria will change bilirubin to yellow/orange and then brown stercobilin in several hours. So, normal stool will be brown, but when stool travels through intestine fast (like in diarrhea), it will be yellow or green, since bacteria have no time to change its color.

NOT normal is yellow bowel movement, and also not orange or green bowel movement if they result from rapid intestinal transit. Red, or black bowel movements, if not from ingested substances, result from the blood in the stool. Not normal are also pale/gray bowel movement, or white bowel movement.

Further Reading:

Mucus In Bowel Movement
Find a Causes of Loose Bowel Movements From Medical Symptoms
Bowel Anatomy, Motility, Digestion & Gut Flora
Comparison of Normal and Loose Bowel Movements
Foods to Avoid In IBS
Fructose Malabsorption