The blue pigment on the stela was identified as Egyptian blue, composed of silica, copper, and calcium. It's a synthetic pigment made by heating silica, copper alloy filings, lime (calcium oxide), and an alkali like potash or natron, which is naturally found in Egypt's Wadi El Natrun. The green pigment is Egyptian green, specifically Wollastonite (CaCuSi3O9), as confirmed by XRF analysis. In summary, the stela's blue and green pigments were both synthetically produced and characterized through XRF analysis.