It is well known that aluminum is a silver-white light metal, while industrial aluminum tubes come in a variety of colors. Why do they have different colors? What are the differences among different colored aluminum tubes? What if the color fades? If you are troubled by these problems, the following

It is well known that aluminum is a silver-white light metal, while industrial aluminum tubes come in a variety of colors. Why do they have different colors? What are the differences among different colored aluminum tubes? What if the color fades? If you are troubled by these problems, the following