I am recently revamping my site to fully optimize and came across something that I thought rather interesting. I am aware of the black hat techniques that users may use to hide the same color text as the background however what if your using lets say white text on a background image and your background behind the image is also set to white? How do search engines know what color background image you are using?... or is it a good idea to stick with a text thats not the same color as the background in general even though the background image is a different color? Thoughts?