Color-based Sudoku puzzle game with 104 puzzles across 5 difficulty levels
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Game tool
Track your solve times across all 104 ColorKu puzzles with stats and achievements
Solve a 9x9 Sudoku grid using colored marbles instead of numbers. Place marbles so every row, column, and 3x3 box contains all 9 colors exactly once. Solve time is the score; faster is better.
ColorKu is a color-based version of Sudoku. Instead of filling in numbers 1 through 9, you place 9 differently colored marbles on a wooden 9-by-9 grid so that every row, every column, and every 3-by-3 box contains all 9 colors exactly once.
The game comes with a set of 104 puzzle cards across 5 difficulty levels, from easy to extreme. Each card shows a starting arrangement of pre-placed marbles; you fill in the rest using logic. It is a single-player puzzle game, and performance is measured by solve time.
Published by Mad Cave Birds, ColorKu is suitable for ages 8 and up. Solve times range from a few minutes for easy puzzles to 30+ minutes for extreme ones.
Wooden board with a 9x9 grid (81 marble recesses), divided into nine 3x3 boxes by raised borders.
81 colored marbles: 9 each of 9 different colors.
104 puzzle cards (numbered 1-104), each showing a starting layout.
Card holder (optional) to display the current puzzle card.
Choose a puzzle card and place it in the card holder.
Place the starting marbles on the board as shown on the card. These are the "given" clues and cannot be moved.
Set the remaining marbles aside, sorted by color, for easy access.
Fill every empty space on the board with the correct colored marble. The rules are identical to standard Sudoku:
Every row (horizontal line of 9) must contain all 9 colors exactly once.
Every column (vertical line of 9) must contain all 9 colors exactly once.
Every 3x3 box (the 9 thick-bordered regions) must contain all 9 colors exactly once.
| Level | Puzzles | Description |
|---|---|---|
| Easy | 1-14 | Many given marbles; straightforward logic |
| Moderate | 15-38 | Fewer givens; standard techniques |
| Challenging | 39-64 | Requires scanning and elimination |
| Tough | 65-88 | Advanced logic chains |
| Extreme | 89-104 | Fewest givens; expert-level reasoning |
Start with easy puzzles to build confidence.
Use elimination: for each empty space, figure out which colors are already in its row, column, and box. Often only one color remains.
Look for naked singles (a space where only one color can go) and hidden singles (a color that can only go in one space within a row, column, or box).
If stuck, try a different area of the board.
ColorKu uses solve time as the score. Lower (faster) times are better.
Solve time in seconds or minutes:seconds.
Puzzle number (1-104) to identify the specific puzzle.
Solve time.
Puzzle number.
Difficulty level (Easy, Moderate, Challenging, Tough, Extreme).
If two players have the same solve time on the same puzzle, they share the rank. In practice, solve times are precise enough that ties are rare.
Select the Standard variant.
Add yourself as the sole player.
Enter your solve time (the system records time-based scores).
The system ranks by lowest (fastest) time.
Tip: Note the puzzle number so you can compare times on the same puzzle across sessions.