As we mentioned earlier, oil paints are sensitive to direct sunlight. The ultraviolet rays can burn the color and make them dull over time. However, oil colors with a high lightfast rating are more resistant to UV light than regular oil paints.
Lightfast rating essentially highlights the ability of oil colors to screen out and withstand UV rays. Hence, if you choose lightfast oil colors, they’ll last for a long time and won’t fade away any time soon, even when they are exposed to direct sunlight.