UPDATED 28 OCTOBER 2026 · MAP CHART EDITORIAL
Colour should help readers understand a geographic pattern. Choose a palette according to whether your regions represent categories, ordered values or differences around a reference point.
Categories need distinct colours
For categories such as service areas or travel groups, use colours that are different enough to identify independently. Avoid assigning similar shades to unrelated groups. Give every group a meaningful name in the legend and keep labels readable against both light and dark fills.
Numerical values need an order
For a measure such as percentage coverage, choose a sequence from lighter to darker. Readers should be able to infer low and high without memorising five unrelated colours. If your data has an important midpoint, such as zero change, consider separate colour directions around that midpoint and adjust your categories deliberately.
Make missing data visible
A region with no value is not the same as a region with a value of zero. Keep missing regions neutral and explain that convention in the subtitle or footnote. Verify that imported empty values did not accidentally become zero.
Do not rely on colour alone
Add clear category names, labels where appropriate, and patterns when they improve readability. Check a grayscale preview if the map will be printed. Very pale fills can disappear on a white background and thin borders can become invisible in a small export.
Reuse a consistent palette
Use Save palette to keep group colours and names for future maps. A project backup includes its colour groups so you can reuse them on another device. Consistency across a report makes maps easier to compare, but only reuse the same numerical legend when the intervals genuinely match.