.A solution that serves as a pH indicator may be made using red cabbage, which is frequently available in homes. In essence, the color of the cabbage depends on the acidity of the solution and a pigment molecule called flavin or anthocyanin.

To determine whether a material is an acid or a base, red cabbage indicator is a purple-colored solution

Vinegar is an acid and its pH value is less than 7 and hence

Red color is produced

Baking soda is base and its pH value is greater than 7 and between 8-9

and the color produced is sky blue

Bleach is the green which is also a basic and because the pH value is 10-11

Householder cleaner is having pH 11-13 which is basic and hence the yellow is the color of household cleaner .

A basic solution goes away from being basic and toward the center of the pH scale when an acid is introduced. The base is "neutralized" in this manner.