I have the following MatrixPlot for which I want to specify a custom color function:
MatrixPlot[RandomReal[1, {10, 10}], ColorFunction -> customColorFunction]
The function should behave as follows: White only for a value smaller than 0.2. Then for the range of >0.2 to 0.7 it should be a continuous blend from red to blue and for the range >0.7 it should be black.
Is it possible to specify something like this with Blend or some other function?