KnowrapH indicatorLinked fromLinked fromThe 5 pages that link to pH indicator, each with the reason it gives.All 5Related 3Narrower topic 2Bromothymol blueNarrower topic: Bromothymol blue is used to estimate pH through a visible color change.Indigo carmineNarrower topic: Indigo carmine changes from blue to yellow across strongly alkaline pH conditions.