Sequential ramps

Use a single-colour ramp for quantitative differences in one measure, such as rates or densities, and for ordered categories, such as “low – medium – high”. To use one with continuous data, bin the data first. Light means low and dark means high.

Every data colour has a ten-step ramp. Step 6 is the base colour.

Teal 1#EBF3F1

Teal 2#D6E7E4

Teal 3#ADCFC9

Teal 4#85B8AD

Teal 5#5CA092

Teal 6#338877

Teal 7#296D5F

Teal 8#1F5247

Teal 9#143630

Teal 10#0A1B18

Which steps

Don’t pick shades by eye. Use these fixed step sets, which are the same ones the colour picker uses:

Steps needed	Use steps
2	2, 6
3	2, 4, 6
4	2, 3, 4, 6
5	2, 3, 4, 5, 6
6	2, 3, 4, 5, 6, 7
7	2, 3, 4, 5, 6, 7, 8

For example, Teal with three and five steps:

Teal 2#D6E7E4

Teal 4#85B8AD

Teal 6#338877

Teal 2#D6E7E4

Teal 3#ADCFC9

Teal 4#85B8AD

Teal 5#5CA092

Teal 6#338877

Use five or six steps at most. Seven is the practical ceiling: beyond that, readers can’t reliably match a shade to its legend entry.

Which ramps

Use the ramps of the four dark data colours: Teal (default), Baltic, Cherry and Violet. Their base colours sit in the middle of the lightness range, so their steps spread evenly from light to dark.

Baltic 2#D5DEEB

Baltic 3#AABDD7

Baltic 4#809DC3

Baltic 5#557CAF

Baltic 6#2B5B9B

Cherry 2#F2D8DB

Cherry 3#E4B1B7

Cherry 4#D78A94

Cherry 5#C96370

Cherry 6#BC3C4C

Violet 2#E7D6EE

Violet 3#CFADDD

Violet 4#B885CC

Violet 5#A05CBB

Violet 6#8833AA

Jasmine, Coral, Sky and Blush have light base colours, so steps 1–6 of their ramps all look pale and the standard step sets barely differ. If you use these ramps, shift the steps into the dark half (for example 4, 6, 7 and 8) and check that every class is distinguishable.

Don’t put two ramps with similar hues in one visual: Teal and Sky, or Baltic and Violet.

For how many steps people can tell apart, see Colour research.