Does exterior anodized aluminum appear to change color under different light conditions?

Many factors influence the appearance of anodized aluminum architectural components. Many architects and designers find that to be one of the attractive features of anodized aluminum: their buildings assume a slightly different character depending upon the weather, the time of day, the season of the year, or the angle of observation.

Differences in appearance will also be influenced by the alloy, anodic film thickness, surface texture of the aluminum from the mill supplier (mill finish surface roughness, longitudinal versus transverse surface roughness), and the process of the anodizer (clean and anodize, etch and anodize, bright dip and anodize, and combinations). Critical to all this is the angle of observation, especially as it relates to the primary source of illumination.

If the product is colored, another level of complexity is added, since the shade and hue must also be controlled. Furthermore, if the material is being used as a light reflector, very specific photometric specifications are usually required.