Yellow/gold clan tag?

Yes, it's possible to make your clan tag yellowl. No, it's not a hack/mod/whatever.

here is what you do.
first go to callsign


then to "Elite Clan Tag"



if you were invited to a clan (and it reaches level 10 through) COD Elite then this should make your clan tag yellow.

Beware you will get asked in every lobby how you did that.