Is darkening hair with tea safe?

Hhahah, so a few days ago I asked how to lighten my hair with lemon juice. I don't know why, because I've always liked dark hair.



Anywayyyy so I've heard I can soak my hair in black tea to darken it - BUT I was wondering:



1. How dark will this make it? I know I can do it repeatedly to make it darker, but how dark would the first soak be?



2. Is this safe for my hair? I've heard it can make my hair shinier, so it sounds safe.. but is it?



Thanks :)xIs darkening hair with tea safe?
2] it is safe for your hair, what harm can tea leaves do?

1] if you have light brown hair, after soaking your hair it will be medium brown.