This is from the Prisma website: Can Prismacolor Colored Pencils be used on fabric?
The Prismacolor Premier Colored Pencils were not designed for use on fabric. Since they are waxed based pencils, they probably won’t hold up to washing and drying; however, some of the pigments used in the colored pencils MAY stain clothing.
from me: So, just don't plan on washing, maybe frame it! Your drawing is very beautiful!