Make default palette better for white background

[HEnquist]

The default palette looks ok in terminals with the dark backgrounds that nearly everyone uses. But macOS is of course different, with a white background as default in the terminal. There is looks like this:

I have played around a little and found that color number 27, light-ish blue, works well on both white and black. The added advantage is that it's easier to tell INFO and DEBUG apart (on dark backgrounds I mean).

[emabee]

Thanks for the proposal - the new version 0.19.0 already comes with the improved default palette!

[HEnquist]

Wow that was fast :)