What are the best practices for using color in bar charts?

1 Why color matters

Color can help you highlight the most important information, create contrast and harmony, and communicate meaning and emotion. However, color can also distract, mislead, or overwhelm your viewers if used poorly. For example, using too many colors can make your chart look cluttered and hard to read, while using the wrong colors can create false impressions or bias. Therefore, you need to be intentional and strategic when choosing and applying colors to your bar charts.

2 How to choose colors

The first step to using color in bar charts is to choose a color scheme that suits your data and your purpose. There are different types of color schemes, such as sequential, diverging, and categorical, that have different effects and implications. Sequential schemes use colors that vary in brightness or saturation to show a progression or order, such as low to high values. Diverging schemes use two contrasting colors that diverge from a neutral midpoint to show a difference or polarity, such as positive and negative values. Categorical schemes use colors that are distinct and unrelated to show groups or categories, such as different regions or products.

To choose a color scheme, you need to consider the nature and distribution of your data, the message and tone you want to convey, and the preferences and expectations of your audience. You can use tools like ColorBrewer or Adobe Color to find and test color schemes that are appropriate and effective for your bar charts.

3 How to apply colors

The next step to using color in bar charts is to apply the colors to the bars in a way that supports your data and your story. You can use colors to encode different variables, such as the value, the category, or the trend of each bar. However, you should avoid using more than one variable per bar, as this can make your chart confusing and misleading. For example, if you use both hue and saturation to show different variables, you may create an illusion of hierarchy or correlation that does not exist in the data.

You should also use colors consistently and sparingly throughout your chart. You should assign the same color to the same variable or category across different bars or charts, and use a legend or label to explain the meaning of each color. You should also limit the number of colors you use to the minimum necessary to convey your message, and avoid using colors that are too similar or too contrasting.

4 How to customize colors

The final step to using color in bar charts is to customize the colors to fit your design and your context. You can adjust the hue, saturation, and brightness of your colors to create different effects and moods. For example, you can use warmer or cooler hues to evoke different emotions, such as excitement or calmness. You can also use darker or lighter colors to create contrast or emphasis, such as highlighting a specific bar or group.

You can also modify the colors to suit your medium and your accessibility. You should consider how your colors will look on different devices and platforms, such as screens or print, and adjust them accordingly. You should also consider how your colors will be perceived by people with different types of color vision, such as color blindness, and use tools like Color Oracle or Color Safe to check and improve the accessibility of your colors.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?