Make .gi style slightly darker.
Make .gi style slightly darker.

It's hard to read #005000 text on the green background of new files. This
change makes it very slightly darker to help just a bit.

Testing done:
Tweaked the style inline on my browser and looked at the results.

Fixes bug 3725.

davidt/reviewboard,beol/reviewboard,beol/reviewboard,KnowNo/reviewboard,chipx86/reviewboard,sgallagher/reviewboard,KnowNo/reviewboard,brennie/reviewboard,bkochendorfer/reviewboard,brennie/reviewboard,sgallagher/reviewboard,bkochendorfer/reviewboard,chipx86/reviewboard,reviewboard/reviewboard,beol/reviewboard,davidt/reviewboard,davidt/reviewboard,brennie/reviewboard,chipx86/reviewboard,custode/reviewboard,bkochendorfer/reviewboard,custode/reviewboard,reviewboard/reviewboard,sgallagher/reviewboard,custode/reviewboard,davidt/reviewboard,KnowNo/reviewboard,reviewboard/reviewboard,brennie/reviewboard,chipx86/reviewboard,bkochendorfer/reviewboard,custode/reviewboard,beol/reviewboard,KnowNo/reviewboard,reviewboard/reviewboard,sgallagher/reviewboard