test failure text in status bar hard to read on light themes

[brettcannon]

If you have a failing test, the extension tells you in the status bar. The problem is that the text is yellow and that can be hard to read in light themes. For instance, with Solarized:

(it's harder to read when not zoomed in like in the image.) I assume there's a way to tell what colours a theme has -- or if it's in general light or dark -- so we can adjust accordingly?