Oxidation - Reduction Indicator

pH 8.0 (colorless) - pH 10.0 (pink)

pH 4.2 (pink) - pH 6.2 (yellow)

Potato Starch; Stabilized with Salicylic Acid

pH 3.8 (yellow) - pH 5.4 (blue) Synonyms: BCG, Sodium Salt Solution; 3',3",5',5"-Tetrabromo-m-cresolsulfonphthalein, Sodium Salt Solution

pH 3.0 (red) - pH 4.4 (yellow)

pH 4.0 (colorless) - pH 6.6 (green)

Potato Starch; Stabilized with Salicylic Acid

pH 6.0 (yellow) - pH 7.6 (blue) Synonyms: BTB, Sodium Salt Solution; 3,3'-Dibromothymolsulfonphthalein, Sodium Salt Solution

pH 3.0 (yellow) - pH 4.6 (blue)

pH 5.2 (yellow) - pH 6.8 (purple)

Bogen's Formula; pH 1 (red), pH 2 (rose), pH 3 (reddish/orange), pH 4 (orange/red), pH 5 (orange), pH 6 (yellow), pH 7 (yellow/green), pH 8 (green), pH 9 (blue/green), pH 10 (blue)