Here are some pictures:
A is the original picture, 50% in order to make it fit here.
As you can see only a part of it is in the right colours.
A part of the original scan is the B - with "waves" in it, I have seen
that before and know simply to resize. But you can see the colour
What causes the yellowness and how can I fix it?
It is a HP Scanjet 2400.