The degree of saturation of ground is conventionally measured at discrete points using transducers, soil moisture sensors, etc. In this paper, a novel method was developed to directly measure the degree of saturation of a continuous region of ground by noting the variation in colour of the ground as the amount of moisture in the soil changes. From photo images taken at various soil moisture contents, the colours of the images were converted into numerical values which were then related to known degrees of saturation. The method was validated through vertical seepage tests, where good agreements were obtained between the measured degrees of saturation by tensiometers and those estimated from the proposed method.