Material compatibility is a complex issue that is challenging to analyse, especially when it comes to historic structures undergoing revitalisation. The use of a solution that is incompatible with the existing structure may not only affect its durability, but also directly lead to the destruction of the historic material. One of the important aspects of compatibility assessment is historical and aesthetic compatibility, which is responsible for accurately conveying historical truth to future generations. In the case of earth-based reconstruction mortars, this compatibility primarily involves the analysis and proper selection of the colour and texture of the reconstruction solution, which, in addition to ensuring authenticity, will be resistant to changes under the influence of long-term environmental factors, i.e., radiation, weathering, and leaching. The selected solution should accurately reflect historical truth while ensuring that other requirements for reconstruction mortars, i.e., strength and durability, are met. The method of verifying the historical and aesthetic compatibility of earth-based mortars is presented on the example of ancient stone structures in the Black Sea Basin. The selected solution was subjected to a test application, which ultimately verified its suitability for use in the original structure. Key recommendations were formulated to ensure historical and aesthetic compatibility for earth-based mortars for reconstruction.