if you take a look of the image, you can see that the colored cell is not all painted, but there is empty blue space (white if the row is not selected) at the sides of the cell.
Sam
Ah, I see.
These are "margins".
There are 3 possibilities how to deal with them:
1) Make them zero in HeaderCtrl (AddColumn(...)...HeaderTab().Margin(0)). This has disadvantage that this margin would apply to HeaderCtrl header too.
2) Make them zero in ArrayCtrl::Column (normaly these are not defined and the value is taken from HeaderCtrl, but if defined, it takes precendce. This has disadvantage that you might have to change your Display to add these margins by yourself.
3) Use Display::PaintBackground. This is perhaps the most straighforward way...