change brightBlack to reset get neutral color on dark themes

[kyeotic]

To fix #173.

Grey colors do not show up on solarized dark (and a few others). But the neutral color is already grey.

Here is solarized dark before the change (with some highlighing to show the invisible text)

Here is solarized dark after the change

For extra comparison here is Solarized light before and after

I tested several other themes just to be sure, but since this uses reset() it should be safe everywhere.

[kyeotic]

I forgot to mention, I tried the other grey/black/bright colors, but they produced poor looking reports. White looked ok, but it seemed to break the intention of the muted color brightBlack is supposed to produce. All the actual colors clashed with the green and yellow in the report.

[nchanged]

Good job! Thanks a lot!