Because indicators change colors over different pH ranges, they may sometimes be combined to offer color changes over a wider pH range. For example, "universal indicator" contains thymol blue, methyl red, bromothymol blue, thymol blue, and phenolphthalein.

Do indicators change pH?

Acid - Base Indicators and Titrations

Acid - Base indicators (also known as pH indicators) are substances which change colour with pH. They are usually weak acids or bases, which when dissolved in water dissociate slightly and form ions.

Does pH indicator affect pH?

Normally, the indicator causes the color of the solution to change depending on the pH. ... Solutions with a pH value below 7.0 are considered acidic and solutions with pH value above 7.0 are basic (alkaline).