Okay so first off you need these Programs:

HxD : [ Register or Signin to view external links. ]
EzGt 2.2 for Buttons : [ Register or Signin to view external links. ]
USB xplorer : [ Register or Signin to view external links. ]
Modio : [ Register or Signin to view external links. ]

Step 1. Okay so start off by extracting your profile form Xport360 or usb XTAF.

Step 2. Then drag your profile into HxD.

Step 3. Hit Ctrl F then search for "MOTD".

Step 4. then when you see a Message of the day that says "Check out the new modern warfare2 trailer" you know you found the cod4 one.

Step 5. You will find your custom classes then Put ^1 ect. all the colors are below.

Step 6. then after you have modded your classes drag it into modio and rehash and resign.

Last step : Transfer back to your device !

colors:
^0: black
^1: red/orange
^2: neon green
^3: yellow
^4: navy blue
^5: Cyan blue(sky blue)
^6: Purple
^7: white/pink