color on the stencil buffer

I am working on the application by using stencil buffer.

I drew the big solid sphere and used glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP).

I created the small solid sphere by using stencil buffer glStencilOp (GL_REPLACE, GL_REPLACE, GL_REPLACE).

It worked fine.

Then I drew the vector on the stencil buffer and used glStencilOp (GL_ZERO, GL_ZERO, GL_ZERO).

It displayed the color of the sphere and the
black color on the vector.

How can I change the color of the vector
on the stencil buffer?

Thanks for any reply.