Added, but when logged in, the colon appears in the actual member list.
[
attachment=26507]
AdminCP > Templates > Your theme's templates > Memberlist Templates > memberlist > and find the following;
{$lang->username}
and Change it into;
{$lang->usernames}
Now open ./inc/languages/english/memberlist.lang.php and find the following;
$l['avatar'] ="Avatar";
and ADD the following code just AFTER that;
$l['usernames'] ="Username";
That seems to work, thank you Yaldaram.