Currently missing CNV HMM data due to high coverage variance is rendered in white in the CNV heatmap. Normal copy number of 2 is also rendered as white. This can be confusing and allow mistaken interpretation of the data.

E.g., here is a plot with the default value for cnv_max_coverage_variance:

Here's the same plot but with cnv_max_coverage_variance set to None, showing that lots of samples which appeared white previously were due to high coverage variance: