A ==Key Stage 3=====Meaning===An '''indicator''' is a [[dye]] that changes [[colour]] depending on the [[pH]] of a [[solution]]. ===About Indicators===: The [[colour]] of an '''indicator''' can be used to tell the [[pH]] of a [[solution]].: Different '''indicators''' will have a different range of colours for different [[pH]] values.: A good '''indicator''' can be added to [[solution]] without affecting the [[pH]] of the [[solution]]. If an '''indicator''' change the [[pH]] of a [[solution]] it could not give an [[accurate]] [[reading]]. ===Examples=== {| class="wikitable"|+ These are the colour ranges of different '''indicator''' plants.|-|[[File:NaturalIndicators.png|center|600px]]|-|}