Chessboard Repaint Puzzle

Repaint rows, columns, or 2×2 squares to achieve exactly one black square!

Moves:0

Black Squares:32

Click any square to repaint the 2×2 region with that square as top-left. Click rightmost column to repaint entire row, or bottom row to repaint entire column. Bottom-right corner switches between row/column mode on 3s hover. Hover to preview affected squares!

Legend

White square

Black square

Hover to preview affected squares

⚠️ Spoiler: This solution to this puzzle leverages a parity-based invariant.