Colors are a critical, but a tough-to-do-right part of visualization.
South China Morning Post: Iraq's bloody toll
Pitch Interactive: Out of Sight, Out of Mind
Wikipedia
Axis Maps
Die Zeit: Regionale Arbeitsmärkte
Tamara Munzner: Visualization Analysis And Design (p. 106)
Colin Ware: Visual Thinking for Design
GOOD: Are The Richest Americans Also The Best Educated?
Cool idea, but:
It's not possible to mentally separate color channels!
Scientific American: Physics Or Fashion?
Spiegel Online: Ballbesitz
Moritz Stefaner: Redesign
Stanford Vis Group: Selecting Semantically-Resonant Colors
Get it right in Black + White.
Use color mostly for categories or highlights.
If used for quantities use mostly variation in brightness.
If used for diverging scales, blend over a neutral color.
ColorBrewer
Color Blindness Simulator
Adobe Color CC
IWantHue
Stephen Few: Practical Rules for Using Color in Charts
Lisa Rost: Your Friendly Guide to Colors in Data Visualisation
d3-color
d3.schemeCategory10
d3.schemeCategory20
d3.schemeCategory20b
d3.schemeCategory20c
d3-scale#schemeCategory10
You can find predefined color scales in d3-scale-chromatic.
<script src="https://d3js.org/d3-scale-chromatic.v1.min.js">