When customizing your theme, you can choose to have Windows automatically set colors. It seems to change automatically based on the background you choose. How does this work? Does it sense which colors are in your background image and do color math to figure out what the theme should be?
They analyze the desktop background image and select the color which used the most in the image.
It works the same way as Taskbar button highlights with the icon color in Windows 7 and 8.
Possibly the same solution as it is used in the fairly new iTunes album view. The algorithm by Seth Thompson scales down the image, followed by calculating the Euclidean distance between these pixels in YUV-colorspace. With these distances, the most n-dominant colors can be retrieved. For the color scheme like it is being used in Windows 8, one color will be sufficient. Follow the link for his implementation in Mathematica.
Whatever color appears the most. If you want to know what the theme color will be before switching just separate all the colors and put all of the same colors into globs. Whichever glob is the biggest is the color the theme will be.
I don't really know exactly how it works but I did find a way around it to where you can choose your own colors but still use the 'automatic' setting. Go to the background image you desire, and go to edit it in photoshop or mspaint or any picture editing software you have. on the bottom of the image, put a thin sliver of whatever color you want and then save it and set it as your background again. if it doesnt work, you might have to add more of the desired color to the bottom of the image, but eventually you get the color you want to appear on the 'automatic' setting
