At present, marine scientists employ manual method to estimate the components in coral reef environment,where Coral Point Count with Excel extensions (CPCe) software is used to determine the coral reef components and substrate coverage. This manual processis laboriousand time consuming,and needsexpertsto conduct the survey. In this paper, a prototype for estimating the distribution of sand cover in coral reef environment from still images by using colourextraction methods was introduced. The coloursegmentation called delta E was used to calculate the colourdifference between two coloursamples. Another method used wascolourthresholdby setting the range of sand colourpixels. Thesystem was developed by using a MATLAB software withimage processing toolbox. The developed system was semi-automatic computer-based system that can be used by researcherseven with little knowledge and experience to estimatethepercentage of sand coveragein coral reef still images.