I think there's a difference before black and after. I'm learning
my instructor's curriculum, and there's a method to his madness
therein. I wouldn't accept a purple belt from anyone other than
my instructor, because I'm there to learn what HE has to teach
me, regardless of what others think of my personal skill level.
But there's an exception ... I'll get to that in a sec. Let's say
that as an orange belt, I can peform all techs,forms, basics that
is required for a blue belt. Yet my instructor has a minimum time
in grade before you can test. Then along comes (for example)
Mr Tatum giving a seminar in my school. He feels (and I'm not
saying he'd do this, I just grabbed his name randomly) that I
deserve a blue belt, and hands me a certificate. I would definitely
take the certificate, because heck, it's Mr Tatum's signature, and
it's a hell of a compliment. But I would wear the belt my instructor
last promoted me to, ALWAYS. Because I'm in his school, and
I'm paying HIM to teach me, HIS way.
Now to the exception, as minor as it is. My instructor's instructor
is Huk. My instructor teaches the curriculum Mr Planas has laid
out for him. The students in my school wear a patch that says,
"Parker/Planas Lineage". So a repeat of the above scenario
would carry a bit more weight because in essence, Huk is also
my instructor, is he not? Now I wouldn't be so bold as to tell
my instructor ( the owner of the school ) "Hey! Huk promoted me
to this color, so I'm wearing it". But I would probably (ya never
KNOW .. this is all theory) go to my instructor and try to make a
strong case for wearing that higher belt. And I think my instructor
would probably allow it. He would still have the final say though!
If anyone else promoted me, I'd tell my instructor about it, but I
wouldn't even think about asking if I could BE that rank, cause
I just wouldn't want to, unless it came from him.