Currently, if you want to highlight any cell of a table with border-collapse: collapse by border-color there will get only two borders in needed color.
https://jsfiddle.net/ahtohbi4/vpkst1rf/
But if you could specify an order of rendering borders (e. g. border-order), we could get all borders of the highlighted cell.
.highlighted-cell {
border-order: 1;
}
What do you think about it?