Really don't know man. These are all image files. In this case its in systemui/res/drawable-xhdpi/status_bar_close_off.png
You can google how to find the color of an image. For instance, I used Gimp with this method and it gave me 5dbbfe but I'm not sure if that is correct for our use:
http://www.instructables.com/id/How-to-get-the-Hex-code-for-any-color-on-your-scre/
That is, indeed, the right color. Thanks again.