Performance bar colors in development are difficult to read

The blue text on maroon background doesn't pass accessibility requirements:

It's also pretty unattractive 😄

Screen_Shot_2018-01-11_at_1.28.28_PM

What could we change these colors to? I think it's got a black background on production so we may want to keep them separate.

cc @rymai @sarrahvesselov @cperessini @blackst0ne