Changing color in more than one table cell breaks table layout

• Create a small table, e.g. 2x3
• Enter text in the second row, in both columns.
• Mark both colums using the mouse.
• Change color to, lets say, grey.

Result:
The selected cells are offset by one cell horizontally, resulting in the first column to become removed and the table getting an additional column at the end for just this row.
So the table changes shape and jets a ragged outline (see screenshot)