<p>The analysis of liquid absorption properties provides valuable insights into composition and quality. the quality and purity of fruit juice is crucial for consumer safety and meeting industry standards. However, conventional spectrophotometric techniques can be costly and necessitate specialized equipment, which makes them less within reach. This research presents an economical, multi-wavelength optical analyser intended for effectively evaluating the quality of fruit juice. The device, which analyses light absorption across six wavelengths—red, green, blue, yellow, purple, and cyan—was created using an Arduino microcontroller, a WS2812 RGB LED, and a lux sensor. Preliminary tests using different amounts of blue pen ink were conducted to evaluate the accuracy of the device, demonstrating the system's ability to detect variations in absorption. After that, samples of sugarcane juice were examined using the method, and fresh, diluted, and filtered versions were compared to a benchmark of distilled water. By measuring changes in light intensity, the results showed that fresh sugarcane juice absorbed more light because of its sugar content and suspended particles, whereas diluted and filtered samples showed gradually lower levels of absorption, indicating changes in clarity and concentration. These results highlight the analyser’s ability as an affordable and capable instrument for tracking fruit juice quality in food processing and agriculture. The use of multi-wavelength technique improves sensitivity to diverse absorption patterns, making it useful for identifying adulteration, ensuring beverage uniformity, and potentially broader uses in environmental analysis.</p>