The previous set of blueish colors offered fairly bad contrast with the
charcoal grey background when using the "black" contrast value. To give
a more uniform experience the default "black" color is now charcoal grey
with it's intense variant shifted into a light grey to complement the
intense background, which is charcoal grey shifted into a more intense dark

This should offer overall better contrast, in particular in htop.

BUG: 371068
REVIEW: 129368
CHANGELOG: Breeze color scheme uses better contrasting color for "black" color value