Currently, the blame view of Diffusion colors commits by age, with light green for more recent changes and dark green for older ones. However:

• It uses absolute age to pick a brightness, so if a file was changed once long ago and then many times recently (which, on average, is most files in active/growing projects) we get a few darker greens and many very bright greens. Better might be to divide the spectrum evenly by the number of changes.
• Changing both hue and brightness (e.g., dark orange to bright green) might make the different colors much easier to distinguish.

See also PHI174.