Gray text colors for better legibility/accessibility.

Opaque text color rgb(127,127,127) on dark background is hard to read.

Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Lorem ipsum dolor sit amet, consectetuer adipiscing elit.

RGBA transparent color rgba(0,0,0,0.5) on dark background is much better.

Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Lorem ipsum dolor sit amet, consectetuer adipiscing elit.