Preventing crop loss requires early detection of disease in crops to achieve maximum yield. Fenugreek is an extensively cultivated vegetable which may be influenced by several diseases affecting quality and productivity. This paper discuss an IoT based method for fenugreek leaf disease detection using color sensors interfaced on Arduino Based on the change in the color of leaves that are characteristic of certain diseases, this system can also provide on-time diagnosis and relevant information. This is the main focus of the work, that is, early detection and treatment of diseases is important in improving agricultural processes and preventing vegetables from spoiling. The color sensor enables this method to identify and sort healthy and diseased fenugreek vegetable plants, which determines its control in the early stages of infection. The best way to have an RGB value of fenugreek leaves is to use a TCS34725 RGB sensor with an Arduino microcontroller. These color values are then compared against a dataset (that you culturally built) of healthy leaf profiles and diseased leaf profiles. The technology identifies from hundreds of thousands of samples, whether the leaf is healthy or diseased, and if diseased, what the specific ailment is, based on the comparison. It empowers farmers to prevent vegetable loss and halt the spread of the disease from other plants in a timely manner through interventions like removing infected plants, timely treatment/disease removal, etc.