Many recent maps I have seen have these neat two-way color gradients that can be used to color correlations between continuous estimates.
Here is an example is taken from a recent publication.
Christian Levers, Pieter J. Verkerk, Daniel Müller, Peter H. Verburg, Van Butsic, Pedro J. Leitão, Marcus Lindner, Tobias Kuemmerle - Drivers of forest harvesting intensity patterns in Europe. Elsevier. 1 March 2014 (access: http://dx.doi.org/10.1016/j.foreco.2013.12.030).
I believe those gradients have been generated with
ArcGIS 10.x and I was wondering how I could reproduce such color gradients with freely available GIS tools (or at least those available on Linux)?
Happy to hear suggestions or code snippets.