Web Intelligence cell borders function differently from the borders in Excel. The border in Web Intelligence can have different color from sides. For example, left of two adjacent cells can have gray right border, right can have black left border. The color of the border on the screen depends on the rendering algorithm, i.e. browser, presentation format (PDF, HTML, XLS), View/Edit mode.
To demonstrate this, let's create a report, add a table with three objects to it. Select the middle column and change its borders to be black from each side:
The result can be the following:
You can change spacing between cells and see the cells and the borders:
To make sure that borders are always displayed correctly, set the same color from both sides:
Without spacing, the border will look as desired: