Clan Tag Colors

I see that Clan Tag colors are "Unlocked at Prestige Level 13" but I have seen several clan tags colored blue
that have not even hit Prestige yet--today's example was a full Colonel with a blue clan tag.  Does it mean
that you can't color your clan tag until you've reached Prestige 13 Level 1 or should it be unlocked at Prestige
1 (2, 3, etc etc) Level 13?  Mine are all locked even though I'm a Prestige 1 Level 34 as of today.

Thanks