Color Stainless Steel: How is Stainless Steel Colored?

Stainless steel, often referred to as "Stainless," "SUS," or "STS," is a type of steel alloy with added chromium to prevent rusting. The term "stainless" itself means "without stains" or "rust-free." Thanks to its excellent corrosion resistance and durability, stainless steel is widely used in cookware, kitchenware, and even architectural materials like roofing and cladding. Its low thermal conductivity and heat resistance also make it an ideal material for spacecraft components. Additionally, its sleek, glossy finish makes it a popular choice for interior design and decorative applications. With such versatility, it's no wonder that stainless steel is considered one of the most ideal metals in various industries.

The signature silvery sheen of stainless steel comes from surface polishing after rolling. Depending on the degree of polishing and post-processing, stainless steel surfaces can be classified into different finishes such as hairline, vibration, and mirror. But how exactly can stainless steel be colored?

Methods of Coloring Stainless Steel

1. Chemical Coloring (Inco Method)

2. PVD Coating

1. Chemical Coloring

The reason stainless steel does not rust is due to its oxide layer. When the chromium (Cr) in stainless steel is exposed to air, it forms a protective chromium oxide (Cr₂O₃) layer, preventing further oxidation of the underlying iron. Chemical coloring utilizes this naturally formed oxide layer to create various colors. This method, developed by the British company Inco, is also known as "Inco Color."

Preocess: 1) The stainless steel surface is pre-treated. 2) It is then immersed in an acidic solution to form an oxide layer. 3) The thickness of this layer determines light interference, creating different colors without adding any pigments or dyes. This is a purely natural phenomenon based on the material's inherent properties.
video on Passivation for Stainless Steel

Available Colors: Bronze, Gold, Black, Rose Gold, Blue, Rainbow, etc.

2. PVD Coating

PVD (Physical Vapor Deposition) is a thin-film coating technology, often referred to as vacuum deposition. In this method, titanium ions are reacted with gases inside a vacuum chamber, forming a thin coating on the stainless steel surface. By adjusting the type of gas, amount injected, and processing time, a wide range of colors can be achieved.

For example, when titanium ions react with nitrogen, the resulting coating appears gold. PVD coatings offer high wear resistance and retain color much longer than traditional chemical treatments.
video on PVD Color Coating

Available Colors: Bronze, Gold, Black, Rose Gold, Blue, Rainbow, etc.

❋ Discover the secret behind rainbow-colored metals in the Conc Mixtape!

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Color Stainless Steel Collections #Bronze #RoseGold

Bronze and Rose Gold stainless steel belong to the red-toned family, offering a modern yet mysterious aesthetic. Their subtle hues create a dramatic effect, especially when combined with lighting.

❋ Rose gold steel meets marble Marble & Metal ― bathroom interior

Color Stainless Steel Collections #Black

Black stainless steel exudes a chic and sophisticated appeal. Whether in a matte or glossy finish, its surface reflections create a variety of atmospheres. This color is neither too cold nor too overpowering, making it a harmonious choice in any space.

❋ Curious about the materials used in the references above? Check out the futuristic spaces created with stainless steel (feat. Balenciaga, NoManual)

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