How to make a screenshot from Halo 3 display someones gamertag, change the color, and make a timer?

I seen somebody made a screenshot on Halo 3 that made it change color, displayed my gamertag, and made a timer in the description and I'm wondering how to do it.



But it if I go into the image it gives the code but when I try to do it it replaces the %26lt; and %26gt; with [ and ] does anybody know how to do it?How to make a screenshot from Halo 3 display someones gamertag, change the color, and make a timer?
Its people hooking there HDD to a computer with Xsata or a data migration kit and modding it.How to make a screenshot from Halo 3 display someones gamertag, change the color, and make a timer?
I've always wondered that. But it's most likely bungie workers or hackers