Illuminant A, due to its very low Color Temperature (around 2856 Kelvin) and Spectral Power Distribution (SPD) concentrated in the red and yellow range, falsely makes printed colors appear warm and yellow. This light lacks sufficient energy in the blue wavelengths, causing neutral colors like gray and white to be influenced by a yellow tint. If a print is approved under Illuminant A, it will certainly have a cold (blue) tint under the standard light (Illuminant D50), indicating a serious deviation in Color Management.

Using Illuminant A for print evaluation is a major mistake, as it forces the observer to accept a color shift toward warmth. The standard for printing is D50, which is neutral and has the least color influence. Specialists use D50 to guarantee color fidelity. Understanding the effect of low Color Temperature like A on color is only useful for analyzing Metamerism (the change in color appearance under different lights).