I found the solution myself, I had to add:
VB.NET
DGV_OverzichtHistorie.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.DisableResizing
DGV_OverzichtHistorie.EnableHeadersVisualStyles = False
1. Without DisableResizing, the columnheight will not change.
2. Without EnableHeadersVisualStyles = False, the backcolor of the column will not change.
So OriginalGriff was right from the beginning, Set all the properties BEFORE databind the datagridview.
Anyway, thanks for thinking with me.