An method and system for detecting color changes in fluids detects the color intensities, and includes a white light emitter and a detector that generates signals representing the detected intensity of red, blue, green, and white light. A processor receives the generated signals and calculates values representing the ratio of detected red to white light, blue to white light, and green to white light. The processor further compares the calculated ratios with reference values and generates a signal when the results of the comparison indicate that the ratios differ from the reference values. By generating the ratio of intensity of each received color to the intensity of received white light, the values are rendered virtually self-compensating and thus largely insensitive to variations in temperature and in intensity that may occur over time with aging of the components.
