Is there any way to create our own tiles and set our own color for other tiles on the Start screen in Windows 8.So that we can find the applications and files by their tile color and display our files in start screen using our own tiles?
Tiles for Modern UI apps will use the background color of the application.
Tiles for Desktop apps aren't set per tile.
From here: Set color for desktop application's start screen shortcut, this answer.
For creating custom shortcuts to files/folders as tiles see my question here:
So for example, to add a folder to the start screen, see the answer here, http://superuser.com/a/491169/85165.
Currently, there is no built-in method for customizing start screen tiles in Windows 8. However, with the use of the third-party program: "OblyTile" (found here), you are able to define custom tiles that will open applications.
You are also able to set up shortcuts to folders if you target "C:\Windows\explorer.exe" and set the arguments to the URL of the folder.