Background Changing

Ive seen people who have backgrounds with different colours on some of the texts and so on.

Just wondering how I can change my background a little more then just change the text in it.

Any1 know how to change the text size, colour and text type like "Fat text"  "Italic text" "Underline text"??

Where do I put those text files you showed me?

In what files in the game files i mean.

Thanx for the help guys

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