The rash of chickenpox turns white and pus-filled, which is usually considered a normal change. For typical chickenpox patients, the rash can turn from a clear herpes fluid to a cloudy and broken rash during the herpes period. In more unusual cases, the herpes may turn cloudy and then form a white pustule-like rash that may or may not break down. After the rupture, the infectiousness of the herpes will disappear and the rash will enter its final stage.