Okay, so a bit of a story but i really need the advice.

Today at my church's "youth gathering" club thing, i was talking to the youth choir leader Brittney and her friend Natalie also my friend.  They were telling me that the youth choir this year is getting shirts.  Hot pink for girls and blue for boys.  My worst nightmare.  So i ask her if i can get a blue shirt.  "You're a girl you're getting a pink shirt"
"i don't want a pink shirt.  I hate pink.  I'd rather wear green and stand out from everyone than wear pink."
"Why don't you want to wear pink?"
This is where my best friend helps me come out to them and i walk away because i'm still iffy on coming out.  Later i come back and ask said best friend, "so did you talk brittany into letting me get a blue shirt." 
Natalie sitting there says" Not a chance.  If you want to shave your head and pretend to be a boy maybe then you can have a blue shirt."
How in hell do i respond to that?  How do i tell someone i love she just lost all of my respect?
Where do i go from here?

That's pretty screwed up.
Pathetic as it is, some people are just entirely too caught up in traditional gender roles and strict ideas of what falls into them.

If it were me, I have low tolerance for that ->-bleeped-<-. I would've been all, "Just give me the f***ing blue shirt."

I would go talk to the person and say that if you have to wear a pink shirt you won't be in the choir ... or shave your head ... I wouldn't stop until I got what I wanted.

As for your friend...I'd would tell her that you were hurt by her actions and disappointed.

Shave your head   

Just kidding... I know how you feel... I had to give up some things in my life for the same reasons.

Honestly if I were you I would shave my head to show how serious the issue is and just to spite them. It will put her on the spot.

Well as I came out in my childhood you hopefully won't be surprised at my blunt answer.

Just tell them the truth. Honestly most of you make life so difficult for yourselves by treating this like some kind of shameful secret. I never did. I came right out with it aged five. It rapidly became clear to everyone who dealt with me that I had no shame about who I was and so they pretty well all accepted it and got on with other things.

I honestly believe that more people had that attitude there would be less difficulties.

You could steal a blue shirt. I'm guessing you're still presenting as female, so wearing the boys shirt is going to be turning heads. Are you prepared to be out to a whole church? Is your church tolerant? If it's not safe to be out to these people I wouldn't risk it over a shirt. I went to a Christian school and it was a very transphobic environment. These people may make you a lot more uncomfortable than a pink shirt would. If being part of this church is something you have to do, I would just do my time and leave.