# Why are different colors, according to sugar concentration observed in Benedict's test?

Colors range from green yellow orange to red. How does the sugar concentration and Cu2O concentration cause this? I know Cu2O is red. Why is there a green or yellow color instead of just red or some kind of red?

Benedict's Reagent is just simply $\ce{Cu^2+}$ ions in the form of copper citrate. When Benedict's Reagent finds an aldose (a sugar with an aldehyde group), it can oxidize the aldose to a carboxylic acid. For example:
Since D-Glucose is oxidized, Cu is reduced to a red precipitate ($\ce{Cu2O}$). The colors range form green to red because the original Copper Citrate ($\ce{C6H8Cu2O7^4+}$) is blue in color.