By which colors are biohazard symbols in the medical office identified

Either fluorescent orange or orange-red

Explanation:

The symbol of "Biohazard" in medical office is of following two colors -  

a) Fluorescent orange  

b) Orange-red

These two color signifies that the waste consist of infectious substances that can affect the well-being of a man through infection.  

However, the bags on which these symbols are used can be of varied color for example - white, yellow, blue, gray etc.  

because of