Describe the feature or problem you’d like to solve

I'm using a white terminal background and some output is very low contract and thus hard to read. See the light gray text in the screenshot below.

Proposed solution

The colors should be chosen differently when a light background is detected. The problem has been discussed in #364, previously.

Additional context

GNOME Terminal 3.30.2
Using VTE version 0.54.2 +GNUTLS