In the Data Buffet Map module, you can pick an automatic division of the data range and color ramp used for the choropleths, or specify specific intervals. Colorize the background, empty areas, lines and text.
The Data Buffet Map module offers a range of formatting options, most importantly for the color range assigned to series values. You can also adjust the empty areas, background, borders and fonts. You could construct a high-contrast color scheme for black-and-white printing or accessibility, a low-saturation scheme for color printing, or match your corporate color palette.
Use an automatic gradient for the map colors:
Options » Legend » Automatic Range = selected
When using "automatic gradient," you get a color ramp between two selected hues, which is then segmented into buckets, each with a single color. The data range (minimum to maximum) is segmented in the same way, and each map area is assigned a single color according to which bucket its value falls into.
Example 1: Your dataset contains values between 0.2 and 3.5. By picking three segments, they relate to values of 0.2 to 1.3, 1.3 to 2.4, and 2.4 to 3.5. You ramp between yellow and red, so that a value of 1.5 will fall into the middle bucket, with the color orange.
With an automatic gradient, set the number of segments and colors:
Options » Legend » Range Detail » Segments, Decimals
Pick the number of segments into which the range is divided, and the number of decimal places that will appear in the legend (if shown).
Options » Legend » Range Detail » Gradient » Start, End
Specify the colors for the extreme points of the color ramp. Intermediate segments will have discrete colors picked from the ramp.
Options » Legend » Range Detail » Reverse
This will reverse the colors in the ramp, not the order in which the segments are listed in the legend.
Non-automatic segments:
Option » Legend » Automatic Range = unselected
A control-group called "Range Detail" will appear at the bottom of the panel, where you can define a specific number of segments, and for each segment, its endpoint values, legend and color.
Example 2: Your dataset has a wide range but most of the values are packed into one end, you will want to magnify their differences. Do so by defining smaller intervals and distinct colors.
Example 3: The automatic intervals are inconvenient and ugly (2.0368 to 3.0276, 3.1302 to 3.4094, etc.). You define intervals that are sensible for your purposes: (2.0 to 2.5, 2.5 to 3.0, 3.0 to 4.0, 4.0 to 10.0).
Background color:
Options » Appearance » Colors » Background
The background includes the legend area (if included), so you may need to change its font color for legibility.
Empty areas color:
Options » Appearance » Colors » Empty Areas
This color is used for (a) map areas which have no time series, and (b) areas which have a series, but the value for the chosen period is ND.
Line color:
Options » Appearance » Lines » Color
Set the color of the borders on each map area. You can also set the style (dotted, etc.) and thickness.