I have had a tooth extracted and the gum looks greenish and bad breath is that bad?

Extraction sites can look quite nasty for a few weeks and food can lodge into the socket and feed bacteria. After meals carefully swish or use a syringe with warm salt water or baking soda and usually this will speed healing. Any significant swelling or pain should be reported to your dental professional.

Yes, it is bad! Definitely suggests infection. Get diluted hydrogen peroxide or ozone oil pulling solution & rinse between teeth. Get a good oral probiotic.

Probably OK. But your treating General Dentist or specialist Oral Surgeon, the one that did your extraction, is responsible for your post-surgical care. Please call him/her and report your findings.