While diagnosing a coSMicQC issue I found there was a possible divide by zero error we could resolve or catch more elegantly:

skimage/color/colorconv.py#line=983): RuntimeWarning: divide by zero encountered in matmul
  return rgb @ coeffs

Found within notebook:
https://cytomining.github.io/coSMicQC/v1.0.0/examples/cosmicqc_in_a_nutshell.html