How many people holds a red belt in karate?

A YMCA is not a Taekwondo Association, but a location where Taekwondo may be taught. These classes are done outside the realm of an official Taekwondo dojang (school), yet should be connected to a central authority and governing body through a well established chain of command. The person teaching Taekwondo at a YMCA might be qualified and certified as a Black Belt and/or Taekwondo Instructor, or they might not be.

Any rules pertaining to stripes on a belt would be at the discretion of that Instructor, and the affiliated Taekwondo organization (if any). Each Taekwondo school and association has different rules and procedures pertaining to belt color, order, and stripes, so it would be best to ask your own instructor. While you are at it, check their credentials to verify legitimacy with the backing of an established Taekwondo Federation.