This paper presents the results of archaeometric research on the white and red materials used to decorate some ceramic vessels belonging to the Boian culture, the Vidra and Spanţov phases from the 5th millennium BC, discovered at Hârşova-Tell, on the right bank of the Danube, Romania. Digital microscopy, wavelength-dispersive X-ray fluorescence spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used to identify the morphology, the crystalline phases, chemical formula, and percentage content of each crystalline phase in the white decoration materials and what type of pigment was used to prepare the red paint. The results obtained reveal that the white decorating material in the pottery is mostly made of calcite. It was added after the pottery was fired. Sometimes, powders from burnt bones were also used. The red pigment is hematite. The work contributes to the completion of a puzzle related to the artistic vision of the members of the Boian communities in decorating ceramics with culture-specific motifs, preserving the pattern, and adapting to the local natural resources.