My friend recently encountred a problem adding symbols to his Dark Avanger. He first added the +4CON/-4STR symbol, and a couple of days later, decided to add the +1CON/-1STR symbol as well, to max his CON. WHen he pressed "Draw" button, he got a system message saying: "The symbol cannot be added" or something like that. I never heard of a rule forbidding -5CON. Is there one?
It should be possible... I have +5 wit on my SE. Don't be offended, I'm sure you already know this, but just in case; how many tattoos does he have total? You can have max 3.
I think Stanmir probably hit it right. There are two kinds of dyes. If he tried the lower level dyes, he would get that message. He needs "Greater" dyes.