The gold colour clan tag comes from being in a leveled up clan, as for the gamertags, if thats what you mean by name tags, then normal players shouldnt have coloured ones no.

Colored clan tags are built into elite, a Clan level of ten and you get yellow, and then different colors every so many levels(10? 20?). [CLAN] Gamertag

When the whole tag is colored, that's a modded gamertag.  That user should be reported in the game and through xbox live. [Clan] Gamertag

(Approximated tags bold/italicized.)