I created a forum post, describing the issue in full detail.

Basically, what I want is a logarithmic coloraxis for heatmaps, which is documented to work, but seems not to be implemented (in Plotly 2.35.3 nor 3.0.1).

Fixing the documentation would be the easiest solution, but implementing a logarithmic colorscale/colorbar according to the current (3.0.0) documentation should IMHO not be too hard and would add great value to plotly. (This feature was asked for multiple times in the plotly forums.)