Now you can customize you Mac to look the way you want, you just have to change your Apps or Folder Icons.
To change the icons you will have to search for “free os x icons” on the web, and you will find a lot of websites where you can download icons from. Also you can use almost any picture to set it as an icon.
To Change App or Folder Icon
1. Copy the picture you want to use to the Clipboard using Edit > Copy or (Command + C).
2. Go to the file or folder you want to replace the icon, then choose File > Get Info.
3. At the top of the Info window, click the picture of the icon to select it, then choose Edit > Paste or (Command + V).