In practice it is possible to determine directly the skin colour and hence the ethnic affiliations of the ancient Egyptians by microscopic analysis in the laboratory; I doubt if the sagacity of the researchers who have studied the question has overlooked the possibility.
Melanin (eumelanin), the chemical body responsible for skin pigmentation, is broadly speaking, insoluble and is preserved for millions of years in the skins of fossil animals. There is thus all the more reason for it to be readily recoverable in the skins of Egyptian mummies, despite a tenacious legend that the skin of mummies, tainted by the embalming material, is no longer susceptible to analysis. Although the epidermis is the main site of the melanin, the melanocytes penetrating the derm at the boundary between it and the epidermis, even where the latter has mostly been destroyed by the embalming materials, show a melanin level which is non-existent in the white-skinned races. The samples I myself analysed were taken in the physical anthropology laboratory of the Musée de l’Homme in Paris off the mummies from the Marietta excavations in Egypt. The same method is perfectly suitable for use on the royal mummies of Thutmoses III, Seti I and Ramses II in the Cairo Museum, which are in an excellent state of preservation. For two years past I have been vainly begging the curator of the Cairo Museum for similar samples to analyse. No more than a few square millimetres of skin would be required to mount a specimen, the preparations being a few um in thickness and lightened with ethyl benzoate. They can be studied by natural light or with ultra-violet lighting which renders the melanin grains fluorescent.