Over time, the colors of your SpyderCheckr Color Visor will fade due to exposure to light. This gradual attenuation eventually affects the correctness of color balance in your photographic work. If you notice that the red thumbnail in the FadeCheckr window in the lower left corner of the inside of the CHECKR has changed to a yellow-orange color*, it's time to replace the visors. This gives you the real colors spectrally designed for the 48 patches on both sides to get the best color fidelity in your photos.