All About Anodized Aluminum Colors

What is Anodized Aluminum?

Anodized aluminum is metal that gets a special coat. The coat is made when we put the aluminum in a bath with power. The power makes the top of the metal grow a layer. This layer has tiny holes. The holes can hold color. The layer helps the metal last longer and not get hurt.

The oxide layer is what makes the metal special. It is part of the metal, not just paint on top. This means the color will not chip or peel off like paint might.

Why Anodized Aluminum is Colored

People put color on anodized aluminum for two big reasons:

1. It helps the metal work better
   • Stops sun from making it fade
   • Keeps it from getting worn
   • Helps it not rust
2. It looks nice
   • Makes things match a brand
   • Lets you pick how things look
   • Gives a smooth, even color

The color is not just for show. It helps the aluminum last longer too. This is why so many things we use have anodized finishes on them.

How Anodized Aluminum Gets Its Color

There are three ways to make anodized aluminum have color. Each way makes different kinds of colors.

1. Dyeing Process

The most used way is to put the aluminum in a dye bath. After the metal gets its oxide layer, it goes in a tub with color in it. The tiny holes soak up the color like a sponge.

Types of dyes used:

• Basic dyes – for bright colors
• Metallic dyes – for deep, rich colors
• Fluorescent dyes – for glowing colors

The color can fade if put in the sun for a long time. This way is good for things used inside.

2. Electrolytic Coloring

This way uses metal salts to make color. The aluminum sits in a bath with tin or other metals. Power makes the metals go into the holes.

Colors made this way:

• Bronze
• Black
• Gold

These colors do not fade in sun. They last a very long time. They cost more to make than dye colors.

3. Natural Oxide Tints

Some anodized finishes let the oxide layer be the color. The thicker the layer, the darker the gray tint. These can look clear or light gray.

This way makes very few colors but they do not fade at all.

Available Anodized Aluminum Colors

Standard Color Options

The most used anodized aluminum colors are:

Some colors are shiny. Some are not shiny (we call this matte finishes). The not shiny ones hide marks better.

Custom Colors

You can get in more than just the main colors. If you need a special color, you can ask for it. Companies use Pantone or RAL color books to pick the right color.

Some cool things you can do:

• Two colors at once
• Colors that change when you look from a new spot
• Very light or very dark colors

Did you know? Setting up a dye tank for a new color costs more than $10,000! This is why small jobs with new colors cost more.

Factors Affecting Color Choice

Not all aluminum can have all colors. Here’s what makes a difference:

Alloy Type

The kind of aluminum you use matters a lot. Some kinds work better with color.

• 6061 aluminum takes color well and looks bright
• 5052 has more magnesium in it, so colors look less bright

If you want precision milling with bright colors, pick 6061 aluminum.

Surface Preparation

How the metal is fixed up before it gets color matters a lot:

• If it is bumpy, the color will look bumpy
• If it is smooth, the color will be smooth
• Some ways to fix the metal make it shiny, some make it not shiny

A chemical pretreatment helps make sure the color looks the same all over.

Industry Standards

Big jobs must meet rules. The rules say how thick the oxide layer must be.

• MIL-A-8625 is for things made for the army
• ISO 7599 is for things made in other lands

The rules help make sure the colors will last a long time.

Durability and Maintenance

How long will the colors last? It depends on how they were made.

Color Lifespan

Not all anodized aluminum colors last the same time:

• Dyed colors: Can fade in sun after some years
• Electrolytic colors: Last 20+ years in sun
• Natural tints: Last as long as the metal does

The scratch resistance is the same for all colors. The oxide layer is hard like a stone.

Care Tips

To keep anodized finishes looking good:

• Do not use hard things to clean them
• Use soft soap and water
• Do not use things with acid or base in them
• Keep salt off them if you can

Did you know? Not sealing the colors right can make 40% of color problems in big buildings!

Common Applications by Color

Different colors get used for different things.

Black

Black anodized aluminum is used in:

• Phones (like the iPhone)
• Computers
• Car parts
• Light cases

Apple uses a type of black that has not faded since 2012!

Bronze/Gold

These colors look rich and warm. They get used in:

• Building sides
• Store signs
• Home things like lamp parts
• Name plates

Custom Hues

Special colors get used for:

• Tools made for doctors
• Car parts that show
• Things with a brand color

For parts that need to be the same color as a logo, cnc aluminum alloy parts can be made with just the right color.

FAQs

How to Order Custom Colors

If you need a special color for your custom metal machining job, here’s how to do it:

1. Pick a color from a Pantone or RAL book
2. Ask if the color can be made on aluminum
3. Know that you might need to buy a lot to get a new color
4. Give time for tests to make sure the color is right

If you need just a few parts, it may cost less to pick a color that is made all the time.

The Science Behind Anodized Colors

The electrochemical process that makes anodized finishes is cool! The power makes the aluminum grow its own oxide layer. The tiny holes in this layer are what hold the color.

• Each hole is too small to see
• There are billions of holes in each inch
• The holes get sealed to lock in the color

This is why the color does not chip off like paint. It is in the metal, not on it.

Cost of Anodized Aluminum Colors

How much does it cost to get colored aluminum? It depends on:

1. What color you want
2. How much you need
3. What shape the parts are

Clear/silver costs the least. Black costs a bit more. Bright colors cost the most.

If you need aluminum cnc machining with colors, the cost of the color is just a small part of the whole cost.

Summary

Anodized aluminum colors make metal look good and last long. You can pick from main colors or get a special one made. The color gets locked in the oxide layer of the metal, so it does not chip off.

The way the color is made changes how long it will last. Some ways cost more but make colors that do not fade.

When you pick a color, think about:

• Will it be in the sun?
• Does it need to match a brand?
• How much can you spend?

With the right color, your aluminum parts will look great and last a long time.