1-Naphthol vs Ext. Violet 2
1-Naphthol and Ext. Violet 2 are both added colour ingredients. 1-Naphthol is found in 1 product while Ext. Violet 2 appears in 1, making 1-Naphthol the more widely used option.
1-Naphthol
Added colour
Ext. Violet 2
Added colour