Recommended color scales

When visualizing spectral data, choosing the appropriate color scale is crucial for accurately representing the nuances and variations in the data. This guide will introduce you to the color scales we recommend for plotting spectral data, helping to enhance clarity, emphasize important features, and avoid common pitfalls like misleading color contrasts.

We aim to use color scales that are diverging or perceptually uniform sequential. Diverging color scales emphasize the difference in the data and perceptually uniform color scales are designed to ensure that the human eye perceives equal steps in data values as equal steps in color intensity. The perceptually uniform scales are particularly important when the data represents a continuous scale where you want to make a quantitative comparison.

Finally, we recommend using a color scale based on red color for plotting potassium, green for plotting uranium and blue for thorium so that it is instantaneously clear what radionuclide is plotted on the map.

Total counts

Spectral and Viridis are often present in popular map-making software packages or plotting libraries.

Perceptually uniform sequential

Viridis
HEX	`#472d7b`	`#3b528b`	`#2c728e`	`#21918c`	`#28ae80`	`#5ec962`	`#addc30`	`#fde725`
RGB	`rgb(71, 45, 123)`	`rgb(59, 82, 139)`	`rgb(44, 114, 142)`	`rgb(33, 145, 140)`	`rgb(40, 174, 128)`	`rgb(94, 201, 98)`	`rgb(173, 220, 48)`	`rgb(253, 231, 37)`

Diverging

Spectral
HEX	`#d53e4f`	#f46d43	#fdae61	#fee08b	#e6f598	#abdda4	#66c2a5	#3288bd
RGB	`rgb(213, 62,` `79)`	`rgb(244, 109,` `67)`	`rgb(253, 174,` `97)`	`rgb(254, 224, 139)`	`rgb(230, 245, 152)`	`rgb(171, 221, 164)`	`rgb(102, 194, 165)`	`rgb(50, 136, 189)`

Potassium

Color
HEX	`#990000`	`#d7301f`	`#ef6548`	`#fc8d59`	`#fdbb84`	`#fdd49e`	`#fee8c8`	`#fff7ec`
RGB	`rgb(153, 0,` `0)`	`rgb(215, 48,` `31)`	`rgb(239, 101, 72)`	`rgb(252, 141, 89)`	`rgb(253, 187, 132)`	`rgb(253, 212, 158)`	`rgb(254, 232, 200)`	`rgb(255, 247, 236)`

Uranium

Color
HEX	`#005a32`	`#238b45`	`#41ab5d`	`#74c476`	`#a1d99b`	`#c7e9c0`	`#e5f5e0`	`#f7fcf5`
RGB	`rgb(0, 90,` `50)`	`rgb(35, 139, 69)`	`rgb(65, 171, 93)`	`rgb(116, 196, 118)`	`rgb(161, 217, 155)`	`rgb(199, 233, 192)`	`rgb(229, 245, 224)`	`rgb(247, 252, 245)`

Thorium

Color
HEX	`#2171b5`	`#3282BE`	`#4292c6`	`#6baed6`	`#9ecae1`	`#c6dbef`	`#deebf7`	`#f7fbff`
RGB	`rgb(33, 113, 181)`	`rgb(50, 130, 190)`	`rgb(128, 125, 186)`	`rgb(158, 154, 200)`	`rgb(188, 189, 220)`	`rgb(198, 219, 239)`	`rgb(222, 235, 247)`	`rgb(247, 251, 255)`

Cesium

Color
HEX	`#4a1486`	`#6a51a3`	`#807dba`	`#9e9ac8`	`#bcbddc`	`#dadaeb`	`#efedf5`	`#fcfbfd`
RGB	`rgb(74, 20, 134)`	`rgb(106, 81, 163)`	`rgb(128, 125, 186)`	`rgb(158, 154, 200)`	`rgb(188, 189, 220)`	`rgb(218, 218, 235)`	`rgb(239, 237, 245)`	`rgb(252, 251, 253)`