The Karim Khani Castle is a monument from the Zand era in Shiraz. In this building, a wall painting is one of the decorations, which unfortunately was hidden under a layer of plaster during the Qajar era, so many studies have not been conducted to identify pigments from the Zand era. The aim of the study is to understand the structure of pigments in the Zand period wall paintings in the Karim Khani Castle. The question raised is what kind of materials are included in the composition of these coloring materials. For investigation, FT-IR, SEM-EDS, and RAMAN instrumental methods were used. The findings indicate that the red pigment compositions included lead oxide (syringe) and possibly iron oxide (late), the blue pigment included ultramarine blue (lapis lazuli), and the green pigment included malachite (mountain green), which were applied on gypsum substrates and an oil-based compound was used as a binder. The pigments have a mineral structure and are durable, and despite the  introduction of European oil paints in Iran, these color compounds have not been used in mural painting.