The risk of Metamerism caused by Illuminant A occurs when a color that looks correct under the print standard (Illuminant D50) appears different under warm, incandescent light like A or Illuminant D65. This phenomenon happens because warm lights like A lack the spectral components necessary to excite all color components. To manage this risk, printing materials (ink and substrate) must be used that exhibit high color stability against severe Color Temperature changes.

Another effective method is transparency with the client; it must be emphasized that the final print evaluation should only occur under the Standard Illuminant D50. Consultants recommend that packaging producers use Illuminant A as a laboratory reference to identify unstable color combinations. This helps to avoid colors or inks most sensitive to warm light, thus maintaining brand color consistency under various viewing conditions, from D50 to A.