Coal mining can increase economic growth, but it can also cause environmental damage through reduced land productivity, including reduced soil chemical properties. Ex-mining land is generally characterized by nutrient-poor soils, low pH, low permeability, damaged structure, and low biological activity, resulting in slow plant growth. This research was carried out in April 2024. This research used a survey method with an exploratory descriptive approach. Soil samples were taken in the field at the location of the acid sulfate land, then samples were taken by grouping the same colour and then recording the RGB value, with a total of 30 samples of the same colour. Soil samples were taken at a depth of 0-50 cm using the purposeful sampling method. Based on the results, there is a relationship between soil colour (RGB and HVC) and soil acidity, Fe solubility and soluble sulfate in post-mining land.