The little research that has been done is encouraging. Neck pain is a problem that is particularly amenable to western 'trigger point' acupuncture rather than traditional Chinese acupuncture.
Acupuncture works at least as well as physiotherapy for chronic neck pain, and possibly slightly better than physiotherapy if the pain is particularly bad.
The redness visible surrounding the needles is a common reaction to acupuncture. It is a sign of local inflammation with an increased flow of blood bringing healing substances to the needled area.