[karmic] Different segments of disk space meter are invisible for some due to poor colour choices.

[Carey Underwood]

Red/orange/green/tan are poor choices in diagrams, as a sizable portion of the population have difficulty distinguishing them.

The marked sections in the attached screenshot are nearly impossible for me to distinguish.

Ideally, the colour scheme should offer significant contrast between each combination of colours. Failing that, easily confused colours should be separated by higher contrast colours so that the boundaries can at least be distinguished.