I am performing a REDOX titration of a diluted bleach sample in my analytical chemistry class. I am using sodium thiosulfate as the titrant to determine the amount of sodium hypochlorite ion in solution. I am using a starch indicator, which is supposed to turn from blue to colorless at the endpoint. The solution itself turns colorless at a point, but excess blue particles, of what i am assuming are starch, still float around. Does anybody know if the endpoint of the titration is when the solution itself becomes colorless, or if by adding excess titrant the endpoint is when the particles in the colorless solution become colorless???