What Is the Importance of Color on the Periodic Table?

Colors indicate groupings of elements, such as valences and abundance

This is a typical colored periodic table that shows element groups.
Todd Helmenstine

Most periodic tables are color coded. You can get black and white or uncolored tables, but mainly these are used when you can't print color or need just the most basic facts about the periodic table and the elements.

Why Color Code?

Colored tables are important because they give you an extra dimension of information. A typical periodic table is colored according to element groups, which are elements that share chemical and physical properties. Some element groups are easily identified as columns on the periodic table, but as you move across the table, the trends aren't so clear-cut. The metalloids and nonmetals, for example, don't fall neatly into the same column. Color coding helps identify similar elements such as these at a glance.

Periodic tables can use color to identify other element characteristics. For example, an electronegativity periodic table color codes the elements based on how electronegative they are. The valence periodic table uses color to identify the most common valence state for each element. The element abundance periodic table shows the relative amounts of each element.

How Are Colors Chosen?

There is no standard set of colors used to identify element groups or other properties. Colors are selected based on how well the text shows up against them, but mostly it's a matter of personal preference. You can find periodic tables in a variety of color schemes.