This is the exact wrong way round. Continuous colour scales are hugely problematic because of the fact that our colour perception is closely linked to context.
If precise comparisons are required you're better off not using colour at all. Colour e.g. in choropleth maps, is good for showing broad spatial trends or highlighting particular areas for selection. A bar chart is better for precise comparisons because we're much better at comparing lengths than colours.
This is the exact wrong way round. Continuous colour scales are hugely problematic because of the fact that our colour perception is closely linked to context.
the classic illustration: http://blog.asmartbear.com/wp-content/uploads/Grey_square_op...
If precise comparisons are required you're better off not using colour at all. Colour e.g. in choropleth maps, is good for showing broad spatial trends or highlighting particular areas for selection. A bar chart is better for precise comparisons because we're much better at comparing lengths than colours.