Esther tells Klaus that 1000 years ago he wrapped his hands around her neck and squeezed until she died, but in The Vampire Diaries (2009), they said that he had ripped her heart out.
When Klaus and Lenore are inside the compound, her hair is completely black. When they are outside, she has two areas of white hair on her part. There are times while they are talking that there is little to no white hair showing.