Repaint an 8x8 chessboard to reach only one black square.

Question

The question I saw is as follow: Assume an 8x8 chessboard. You can repaint all squares of a row or a colum or a 2x2 square. The goal is to attain one black square. Can you reach the goal?

Answer 1

Assuming that repaint means inverrting the color of each square it is impossible.

Notice that initially there are $32$ black squares, notice that every move preserves the parity of the number of black squares.

Answer 2

Yes,

You can do it in 8 steps.

1. repaint every second column (4 steps)
2. repaint white rows (4 steps)