Abstract To the accumulation of evidence of painted decoration applied to Neolithic and Early Bronze Age pottery in Britain and elsewhere in Europe we report here the presence of decoration in red, black and white on some third millennium BC Grooved ware pottery at the Ness of Brodgar on Orkney. As expected, the red was identified as an iron-rich material and black was carbon black. The white was prepared from calcined (cow) bone; however, its identification encountered some issues arising principally from the effects of the prevailing burial conditions on the bone. Furthermore, whereas the chemical and FTIR data were consistent with the presence of apatite, XRD indicated that the white had a significant content of silicate minerals. This finding has suggested that the white required a preparatory step which might have included the calcined bone bring ground to powder in a stone mortar before application to the vessel surface. The results obtained at Ness of Brodgar are reviewed in the light of archaeometric data on similarly decorated prehistoric pottery reported from sites in Europe.