What the woman did (adultery) is black. There is no gray for sin. Adultery, bearing false witness, etc... Christ's compassion isn't what we are talking about when saying "black or white". Christ has showed us His compassion by sacrificing Himself so that we can be made clean again. Sacrificing is no longer needed as He was the ultimate sacrifice.
Demi hits it right on the head when she says that Christs commands her to go and sin no more. He isn't defending her actions, He forgives the blackness (sin) when we exercise the atonement. Thank God for the atonement.