I am using contourf function in MATLAB to get a spatially filled plot with colorbar representing the magnitude of the particular parameter. But the software is discretizing the colorbar evenly. I am more concerned about the features in particular range so want a discretization such that one particular color stands for values between 0-1, another for 1-1.25, then for 1.25-1.75 & 1.75-4. It is to be noted that the intervals of these range are unequal. It would help me a lot if somebody can address this issue.