They are black.
That will depend on your specific school. It is a combination of time and knowing the right skills.
ABSOLUTELY!! It doesnt matter how old you are to join karate and earn belts. There was a woman in my karate class and she was 72 years old.....Karate is for anyone who is willing to learn disipline and respect!
Belts states the level of your expertize in the sport. It also inspires you to work harder to win the next belt!
It will depend on the style of karate being taught at your YMCA. They are not the same everywhere. The instructor will be able to provide you the requirements for the various belts.
i got some from ebay.
green black and red
Yes of course
they have more or less belts
Honestly the best thing to do would be either to get a martial arts catalog (I prefer AWMA but Century would probably be easier to get) and order some from there or use Amazon. Using bath robes and cloth belts just looks dorky and unconvincing.
There are a number of items that can be used to display karate belts. Most are a sort of rack that the belts fit into them. Check a martial arts supply company online and you will find pictures and examples. They are fairly easy to make, and are fairly inexpensive.
Prince and Paris and Blanket are Yellow belts.