There are many tweaks you can do to Windows, and Customizing Folder Background and Icons is one of them. Here is how to do just that.
Choose a File to Show on the Folder Icon
The default folder icon background is a thumbnail preview of the things inside. However, this can be customized and changed to your liking. First, right-click the folder that you want to change the icon background. Select Properties. Click the Customize tab, and click Choose File under Folder Pictures. Browse and find the file you want to show on the folder icon. After selecting the picture, click Ok.
Change the Icon of your Folder
Another thing you might want to do is completely change the icon of a folder from a folder to something else. First, right-click the folder that you want to change and click Properties. Go to the Customize tab, and click on Change Icon under Folder Icons. Select an icon from the list, or click on Browse and choose the new icon that you want applied. Click Ok in the Change Icon Window, and click Ok on the properties window to save your new icon.
Use a Background Picture for your Folder
Believe it or not, you can set a picture to be the background of the folder when you open it or change the way the text is shown. First download this nifty piece of software released by The Windows Club here. Unzip and run the program as an administrator. Select the folder that you want to add a background image to. Then click on Change Background Image and select which image that you want to use. To change your text color, click the box next to Text Color and customize it to your liking. After you do all configuration that you want to, close the application to apply your settings to the folder.