Illuminant A is a standard light source used in color science and photography. It simulates the warm, incandescent light typically produced by traditional light bulbs, with a color temperature of about 2856 Kelvin. This makes it useful for evaluating colors under conditions similar to those found in everyday indoor lighting. The spectrum of Illuminant A is characterized by a continuous distribution of wavelengths, which means it emits light across a wide range of colors. This quality helps in accurately assessing the color appearance of objects and materials, making it a valuable reference for artists, designers, and scientists.