I modified the "external link" indicator for Night mode. Here's how it looks:
https://www.dropbox.com/s/8sebxpjqee02wha/device-2014-07-17-113418.png

I simply took the existing indicator and made its background transparent, instead of white. Technically, since it's transparent now, it can replace the indicator in our general styles, so that we wouldn't need a different one for night mode.  Thoughts?