I had laparoscopy surgery 4days ago and my belly button have yellow color and bruce. And have thick dry blood on surgical site. It is normal?

Sound OK. Following surgery, a small amount of bleeding is normal and it will produce a bruise as well as a scab. The yellowish color i'm not sure of... But, it might be what is left of the skin prep used. If you have increased pain, fevers, redness or drainage- see your doc. Otherwise seems within normal.