If I browse to an image, I would like my web browser to display it on black (not white). How can I do that?
You didn't say you use Chrome exclusively, so for Firefox, you can use the Old Default Image Style add-on. It allows you to specify a custom colour for images, as well as to choose whether to show them in the centre or top-left corner.
There is a chrome extension which allow you to change the behavior of chrome when you open an image: Image to center.
In addition to center the image in the browser instead of having it in the top-left corner, you will be able to select a solid background color of your choice or a checkerboard one like on Photoshop.
It's very useful when you are looking for a well aliased picture as there is a lot of png file with some transparency but which render well only on a white background. So you just lose the interest of having transparency and that kind of pictures are still displayed in the google result with alpha filter.