The elevated standards for architectural and artistic expression, pivotal in enhancing the livability of urban landscapes, are significantly influenced by the innovative characteristics of materials employed in landscaping features and minor architectural structures. This paper delves into the influence of the particle size distribution of photoluminescent pigments on the quality of afterglow observed on the surface of hardened cement paste. Utilizing a method of computer image analysis, the study scrutinized samples with diverse compositions containing varying proportions of photoluminescent pigments. The principal aim of the investigation was to evaluate the uniformity of afterglow luminosity across the surface of hardened cement paste integrated with photoluminescent pigment. Experimental results revealed that the pigment fraction measuring 100-110 μm demonstrated superior uniformity and longevity of afterglow, while maintaining the integrity of the hydration processes within the cement matrix. In contrast, fractions sized 30-40 μm and 180-190 μm exhibited a diminished uniformity in the dispersion of light spots on the surface of hardened cement paste by 79% and 88%, respectively. This discrepancy can be ascribed to variations in the quantity of particles capable of photoluminescence and their distribution within the volume of the cement matrix.