With nowadays' modern technology, manufacturers create HD displays, rich of colors which ofcourse, consume energy. So in this case the inverted mode can be quite helpful in battery saving.
So if you urgently need to keep on browsing while your battery is near death, you can try enabling this option to keep it alive for a little more longer.
1. Let's start off by launching the Browser app on your Android ICS smartphone/tablet.
Next, tap on the little settings icon on the top-right corner and go to Settings:
2. You are now in the Settings menu, take a look at the right side and if you need to, scroll down a bit more until you see the option "inverted rendering":
Once you enable that option, your websites will be displayed in inverted colors:
That is all, if you would like to get back your colors, simply uncheck the Inverted Mode option.