No, you can't change the name color that way, but you can change the color of the clan prefix at least.
well if you do something gimmicky like this you possibly could. i don't recall exactly if this works but it should
%clanprefix = %clanpref @ "<a:";
%clansuffix = "></a>" @ "<color:" @ %color @ ">" @ %name @ "<color:rickroll>" @ %clansuffix;
(yes, <color:rickroll> is a thing. go try it ingame. it happens to be the grey for the clan tags.)