Yesterday, I tried to run ‘npm test’ for a new project and the text was invisible (i.e. the same color as the background color of my chosen color scheme for iTerm2). You can find a long discussion about this problem here: https://github.com/altercation/solarized/issues/220

Buried in this discussion was the solution: iTerm2 -> Preferences -> Profiles -> Colors -> Minimum contrast -> Move slider about a third of the way