Animated Rainbow Usernames

[Nucky]

is tutorial working for mozila 10 i'm testing it and not working in mozilla 26

[IceX]

doesnt work for 1.8.6

[Legitti]

This user has been denied support.

The following errors were encountered:
You can't use script, meta or base tags in the username style.

[Blackbeard]

yup, (i think) this tutorial is outdated and doesn't work for 1.8.

[Midori]

Hi to all
you can go and use [For 1.8] Animated Rainbow or shiny Usernames  for mybb 1.8 .

[PARADOXP]

CSS 3 and HTML 5 should have a way for rainbow text other than javascript. That's my opinion.

.rainbow {
  background-image:-webkit-gradient( linear, left top, right top, color-stop(0, #f22), color-stop(0.15, #f2f), color-stop(0.3, #22f), color-stop(0.45, #2ff), color-stop(0.6, #2f2),color-stop(0.75, #2f2), color-stop(0.9, #ff2), color-stop(1, #f22) );
  color:transparent;
  -webkit-background-clip: text;
}

That's what I'd use, having it animated would be annoying

Where should i add this code ? Please guide me i am a noob.