Feature request: More control over color bounds and color space

[b-zijlstra]

Currently the color-mapping is done logarithmic. The user has an input argument to set bounds, but these bounds are limited to integer values. This is currently done to keep the legend consistent as the integer bounds are taken as log input. However, I've found that non integer values can improve color contrast. This also means that the user might want to deviate from logarithmic color space.