Not readable on light background terminal

[goerz]

The colors appear to be hard-coded under the assumption of a terminal with a dark background. In a light-colored terminal, the light gray text is not readable:

I know there's a -c option, and e.g. -c green produces something more readable, albeit monochrome. I wouldn't mind having the different colors for the different data categories, but with dark text. It's probably a good idea of have options or a configuration file for this, but it might also be helpful to detect the terminal background color if no options are given (e.g., via the COLORFGBG environment variable)