IKI which is also known as Iodine Potassium Iodide is a light yellow colored solution. It is used to detect the presence of starch is a given mixture.
When IKI comes in contact with starch, it changes from light yellow to deep purple.
An indicator is a substance which changes its color at a particular pH, or in presence of a specific compound.
Since IKI is changing color in presence of starch, it behaves as an Indicator.
