Visual indicator composed of a solution of several pH indicators (main components are thymol blue, methyl red, bromothymol blue and phenolphthalein) that changes color through a range of pH values, usually from 1 to 14.
Note:
Universal indicators are commercially available in the form of a solution or in paper strips accompanied by a color matching chart.
Source:
PAC, 2025, 97, 137. 'Glossary of terms for mass and volume in analytical chemistry (IUPAC Recommendations 2024)' on page 8 (https://doi.org/10.1515/pac-2023-0903)