Swap tiles to rebuild a perfect color gradient in the fewest moves.

Color Gradient Puzzle is a hue-sorting game you play right in your browser. Every board starts life as a smooth gradient: the four corner colors are blended across the grid, so the hue shifts from left to right while the tiles get lighter toward the top and darker toward the bottom. Then every movable tile is shuffled. Tap one tile, tap another, and they trade places — keep going until each color is back where it belongs.

Tiles with a small dot are anchors and never move. How many you get depends on the mode: Easy (4×4) pins the four corners plus the middle of each edge, Normal (5×5) and the Daily board pin only the four corners, and Hard (6×6) and Expert (7×7) keep just the top-left and bottom-right corners. Bigger boards also narrow the color range — on Expert the hue and lightness spread is about 60% of Normal — so neighboring tiles look almost identical.

There's no timer; your score is the number of swaps. When the gradient is complete, the game shows the true minimum for that shuffle (worked out from the permutation's cycles) and your efficiency, which is the minimum divided by your swaps. Matching the minimum earns a Perfect, and staying within 1.3× of it earns a Brilliant. The Daily board is generated from the date, so everyone playing on the same day gets the same puzzle, and each mode keeps its own leaderboard.

A reliable approach: sort by lightness first to get each tile into the right row, then order each row by hue. A wrong swap still counts as a move and undoing it costs another, so look before you tap. Colors also depend on your screen — night mode or a blue-light filter flattens the differences — and players with color vision deficiency often find the left-to-right hue steps harder than the top-to-bottom lightness steps.