Abstract: An automated system for measuring plant leaf color, as an indicator of plant health status, has been developed for plantlets growing in a modified micro propagation system. Using a custom builthand device, sensors located on a pan and tilt system at the end of the device monitor plant growth and the ambient growing environment. Sensors include a compact color zoom camera, RGB (red, green and blue) color sensors. Leaf color sensors provide information, in a non-destructive manner, on the health status of tissue by comparing the sensor outputs to pre-determined optimum values. These low cost color sensors can be incorporated into a continuous automated system for monitoring leaf color of growing plants. Subtle color changes can be an early indication of stress from less than optimum nutrient concentrations. When combined with automated image sensing for growth analysis, and environmental sensing (RH, CO2 and temperature) in a controlled environment, optimized rapid growth with minimal human input can be achieved using a modified micro propagation system. In this project we detail the calibration technique for a RGB sensor and compare it with a high end