What does the color of transformer oil indicate?

The color of transformer oil is an important indicator of its condition and performance characteristics. Typically, new transformer oil appears to be pale yellow or clear, indicating purity and proper refining. As transformer oil ages or becomes contaminated, its color can darken, turning to shades of brown or black, suggesting the presence of oxidation products, impurities, or the breakdown of insulation materials. Therefore, monitoring the color of transformer oil is crucial for assessing its quality and determining when it may need cleaning or regeneration to maintain optimal performance in electrical systems.