Hi Kevin, thanks for your reply. Let me clarify things first, I should have said before that my sound color is dark, but not to the extent of a real alto. The thing is that, for some strange reason, there are no real altos in my country, and if there are, they are extremely rare, so anyone with a dark sound color is sought after to perform mezzo or alto roles, even when they are not real ones. I heard someone say that altos are only common in cold countries, and I live in Ecuador, which probably needless to say, is NOT a cold country at all, it never gets so cold that you need heating or big coats.
I have spoken to many, many vocal teachers, and everybody has said that I'm a soprano but with a dark sound color, only one person (out of probably 10 who have listened to me) said that I probably am a mezzo, so I really doubt I could be a mezzo or an alto.
This choir has many sopranos already, and many of them are very light sopranos (that's what's the most common here) so they said that they want me to sing mezzo or alto.
So that's why I'm asking about this, if it would be safe or not, because I've heard a couple of people saying that it's not good to sing in a register that is not yours, but honestly, I don't agree with this, now that I know about cvt, so I just wanted to make sure that it would be safe for my voice to sing alto or mezzo roles without feeling guilty.