The new top bar layout is fine, but the black color is very visually jarring/intrusive. Is using a lighter color an available option?
It fits well on some sites. On most sites, it's indeed jarring. Beta sites, for example — all light blue/cyan/gray colors except for that black* band.
The color of the top bar should be adjusted for each site, to fit the site's theme.
* Yeah, I know, not black.
Make it transparent (suggestion originally from Sci-Fi meta):
Currently, this is not an available option.
But, as a workaround, userscripting should get you pretty far. Then you can have all the color-goodness you like. And let's be honest here, you really want it to be pink.