Anodizing color hard to match and fade
In aluminum industry, color surface is needed sometimes. In consumer industry can see black most common, also red on iPhone, purple, pink battery bank, bronze window etc.
In solar racking industry, black matches with black silicon high efficiency panel in black color, all black creates a high end feel. But there is always 2 pain points as color hard to match and fading.
It is important to note that colors obtained through dying are not as consistent as those obtained through painting or powder coat. There is no such thing as a pantone matched color in most commercial anodizing, and consistency in color and color matching is extremely difficult. Generally, colors are specified in a broader way than with painting, e.g., you would specify “blue” or perhaps “light blue” or “dark blue” for an anodized part, not “deep sky blue” or “electric indigo blue”. Note that colors obtained through organic dyes are not absolutely colorfast, especially in high UV exposure situations. All organically dyed parts will fade to some degree over time. Outdoors, the fading can be dramatic.
Dying in Fade–resistant Architectural Anodizing
There is a second, less common dying process known as 2-step electrolytic dying. In this process, the anodizing layer is the same as regular Type II anodizing, but at the dying stage, instead of organic dyes, inorganic metallic dyes are used in combination with an electric current. While the range of colors is far more limited than with organic dyes (generally light through very dark, nearly black bronzes), the colors are extremely resistant to fading, and will last indefinitely even in very high UV environments.
Photo: Two black end clamp, after being placed in intense direct sunlight for about 8 months. Both parts started with a similar black color. The bottom part used common organic black dye and has noticeably faded. The top part was dyed using a 2-step electrolytic process (“architectural anodizing”) and shows no fading.