Unsure if this is intended or not. But i was struggling with the datatable. When i selected something it became almost black. Took me a while to realize it was the background color to the page that was bleeding through.
Here is an example of this happening halfway through a cell.
I added anther background color to show the contrast.Soloution was just to add white to the div that contains the table. But im guessing there is something that selected attribute does that makes it take the color of the background.