[Papero]

You need to leave the "HexTags" start es:

//..//
"HexTags"
{
        "Default"
       {
		"ChatTag"	"{purple}[Admin]"
		"ChatColor" "{lightgreen}"
		"NameColor" "{orchid}"
        }
	"@Admin"
	{
		"ScoreTag" "[Admin]" //The scoreboard-tag
		"ChatTag"	"{red}[Admin]" //The chat-tag
		"ChatColor" "{darkblue}" //The chat color
		"NameColor" "{grey2}" //The name color
	}
}