Change color used for standard output text.

This alleviates an invisible text problem in some themes.

Many themes have trouble with the Grey ANSI color 90 that is being used in dev output.

I'm seeing this in Solarized Dark, but it is a problem in other themes as well.

Changing from 1b[90m to 1b[92m fixed the problem for me.

Last year Bower made a similar change for the same reason.