Themes designed for Windows 8 comes with an auto-color feature that smoothly and automatically shift the Windows desktop title bar and taskbar color to match the dominant color in whichever background image is currently being displayed. While it is possible to install themes made for Windows 7 on Windows 8, this auto color feature becomes unavailable when you do so.
ThemeConverter for Windows 8 is a small utility that lets you convert “normal” Windows 7 themes into Windows 8 auto-color themes by injecting the right parameters into the theme file.
Install the themes like you do in Windows 7. Then run ThemeConverter for Windows 8. Pick the theme you want to auto-color and then add the auto-color setting with a single click. Now head to theme Personalization settings from the desktop and choose the auto-color option.
Auto-color is optional feature and can be turned off under Personalization options.