There is provided on-demand, oxygen generating topical compositions having a built-in indicator specifically to indicate a color change upon the complete mixing of the oxygen precursor and catalyst. The first part of the composition contains a carrier and manganese dioxide (MnO2) nanoparticles. The second part of the composition comprises the oxygen precursor hydrogen peroxide. When the two parts, one with manganese dioxide nanoparticles and exhibiting a characteristic color, (e.g. yellow brown) and the second part with hydrogen peroxide are mixed together, the color imparted by the manganese dioxide nanoparticles essentially disappears and the final composition (enriched with oxygen) either appears colorless or takes on the original color of the catalyst. Thus, the manganese dioxide catalyst nanoparticles themselves serve as the colorimetric indicator of peroxide decomposition to oxygen, precluding the need for an external colorant. Manganese dioxide particles that are not nanoparticles fail to exhibit this color changing phenomenon.
