Iron color is said to be "a color like iron burnt skin" in JIS idiomatic colors, but it is one of the colors whose origin of the color name is not clear.

There is also a theory that it is not a color imagined from so-called "iron", but a dyeing color that uses iron as a type of indigo dyeing.

The colors with iron names, such as iron navy blue and iron sheds, have a dull blue-green tint.