Within methods of chemistry, the most common and obvious way to find the PH of a substance is to use an acid-base indicator in order to determine the pH level by comparing the indicators color to what pH it represents. An example of this is universal indicator (a mixture of a variety of other indicators) that changes a wide variety of colors depending on the pH it is subject to. This colorizing effect is somewhat like a color dye for a molecule, that changes color when it detects a specific threshold is crossed in terms of the pH of the substance, thus allowing an approximate pH to be determined. This color change is due to the molecules present in acid-base indicators responding to the changes in the overall concentration of the hydrogen
