I am working on a D3 bar chart as per the mock-up below:
How do I make the bars to have rando
this is old now, but this is a pretty good approach if you need N number of random colors
http://bl.ocks.org/jdarling/06019d16cb5fd6795edf
d3 has 4 built in color palettes.
Here's the link for the built in color palettes.
This tutorial is good on using specific colors for specific element.
Another tutorial by Jerome Cukier.
And the official site for d3 colors.
Fiddle - Note: In the fiddle I've passed the colors by adding colors in the data.
It can even be done by passing the colors from a different variables.
Hope this helps.
colors = d3.scale.category20()
rects = svg.selectAll('rect')
.data(data)
.enter()
.append("rect")
.attr("class","rect")
.....#other attributes
.attr("fill",function(d,i){return colors(i)})