Pima County Geographic Information Systems

Autodesk MapGuide Color Anomalies

The set of 256 MapGuide colors defined by Autodesk has several anomalies:

• The first 16 numeric color values are a disjoint set of colors which includes WHITE. These first 16 colors are followed by 16 sets of color hues in groups of 15, with each of the following groups having a relatively smooth intensity range for the hue.

• 11 of the first 16 colors duplicate colors are defined again with different color numbers in the rest of the chart. These can be seen by checking "Cross reference duplicate colors" above. It's not clear why Autodesk chose to have only 245 unique colors (256 less 11) in the table when they could have had 256 unique colors.

• 4 of the first 16 colors are unique colors that do not duplicate colors defined in the rest of the chart. Checking "Insert base colors in color sequence" displays those colors in the rest of the chart where they should be based on their color. Note that the displayed colors vary smoothly with these insertions, but the color numbers of the inserted colors are not in sequence. Knowing where these 4 colors fall within the ranges makes them more usable for selecting colors in the ranges.

• There appears to be an unusually large difference between colors 83 and 84. That is, the colors in the yellow range aren't evenly distributed. Color 228 looks out of place, perhaps belonging between 212 and 213 instead. That's the way it is...

By checking "Insert base colors in sequence" before showing the color chart, you can ignore the first displayed set of 16 colors (except for WHITE) and know that you are choosing from the full range of available colors in the rest of the chart's smooth color ranges. This is because all of the first 16 colors (except WHITE) are either already duplicated by Autodesk or have been inserted into the chart in their proper color sequence. However, you may find it easier to select from the first displayed set of 16 colors for simple (and coarse) color selection.