Disclosed are treatment composition, comprising an aqueous continuous phase; a reactive component comprising a reactive agent and a water immiscible solvent, wherein the water immiscible solvent solubilizes the reactive agent; and one or more surfactants wherein the surfactants emulsify the reactive component in the aqueous phase to form a bi-layer emulsion. Also disclosed are methods for treating amino acid based substrates, and methods for bleaching, coloring and conditioning hair with these treatment compositions.