What does the colour of precipitate in the Benedict's test tell you?

The Benedict's test is used to test for simple carbohydrate's (monosaccharide's mainly, some disaccharides). It can also be used to test for the presence of glucose in urine.

If no sugars are present it will remain blue. Green/Yellow precipitate indicates traces of sugars, Orange precipitate indicates moderate sugars, and a brick red precipitate indicates large amounts of sugars.

These sugars are referred to as reducing sugars, because they are capable of transferring hydrogen atoms (electrons) to other compounds. This process is called reduction.