Codoku
Puzzle Contains ads
9x9 logic puzzle: fill rows, columns, & 3x3 boxes with colors without repeating.
- Downloads
- 17.3K+
- on Google Play
- Price
- Free
- No in-app purchases
- Updated
- Oct 22
- 2026 · v1.7.0
Screenshots
About Codoku
Codoku: Colors Sudoku is a vibrant, logic-based puzzle game that strips away traditional numbers and replaces them with a spectrum of distinct colors. By swapping digits for visual elements, the game transforms classic grid deduction into an engaging, pattern-recognition challenge that exercises visual memory and spatial reasoning. [1, 2, 3, 4, 5]
Core Gameplay Mechanics
The game takes the foundational mechanics of traditional Sudoku and maps them to a multi-colored layout. Instead of relying on numerical tracking, players must think visually. [6, 7]
* The Rainbow Grid: The puzzle features a standard 9 × 9 layout. This major grid is split into nine standalone rows, nine vertical columns, and nine smaller 3 × 3 zones. [1, 7]
* The Objective: Fill the entire board so that each row, column, and 3 × 3 zone contains nine distinct colours without a single duplicate. [1]
* The Starting Setup: Each puzzle boots up with a fixed set of pre-placed colour blocks. These "clues" are locked into place and cannot be altered or moved, serving as your logical anchor points for the rest of the board. [1, 7, 8]
* Pure Deduction: No mathematical calculations or counting are required. Victory is achieved entirely through the process of elimination, pattern tracking, and careful visual placement. [2, 9, 10, 11, 12]
How to Play & Basic Strategy
Because your brain registers hues differently than it does numbers, the mental approach shifts away from counting to spatial scanning.
1. Isolate a Single Palette: Focus your attention on one specific colour at a time. Trace its pre-existing positions across the board to figure out where its placement is restricted in adjacent zones.
2. Scan the Boundaries: Look for rows, columns, or 3 × 3 sections that are already heavily crowded with colors. The fewer open slots a region has, the easier it is to deduce which remaining shades fit perfectly. [1, 6, 13]
3. Cross-Reference Intersection Points: If a particular cell sits at the intersection of a row and column that collectively display eight of the nine possible variations, that cell's true identity is immediately revealed by the process of elimination. [7, 13]
Key Benefits & Audience Appeal
Codoku alters how the brain processes logical constraints, offering unique advantages over its numerical predecessor:
* Overcoming Math Anxiety: Many individuals shy away from traditional puzzles because numbers feel intimidating. Codoku provides an identical cognitive workout using purely artistic and visual cues.
* Brain Activation: Studies on colour-based puzzle games reveal that tracking vibrant hues activates a broad network across multiple brain lobes. This balances spatial recognition with hard logic.
* Accessibility for All Ages: The visual layout makes the game highly intuitive for children. It acts as an excellent tool for developing early problem-solving skills, and its scale can be adjusted down to a 4 × 4 or 6 × 6 layout for beginners.
* Digital Convenience: Modern digital adaptations feature responsive click-to-select palettes, clear mistake highlighting, and hint mechanisms designed to keep gameplay moving seamlessly without the mess of paper and pencils. [2, 7, 14, 15]
Essential Rules to Remember
* Each color must appear exactly once per horizontal row.
* Each color must appear exactly once per vertical column.
* Each color must appear exactly once per bordered 3 × 3 box.
* Locked starting blocks cannot be modified. [1, 7, 16, 17, 18]
If you want to dive deeper, let me know:
* Would you like tips on designing a physical DIY version using tiles or pegs?
* Are you looking for a python algorithm to automatically solve colour grids?
* Do you want to see how to handle advanced strategies like color-chain linking?
Core Gameplay Mechanics
The game takes the foundational mechanics of traditional Sudoku and maps them to a multi-colored layout. Instead of relying on numerical tracking, players must think visually. [6, 7]
* The Rainbow Grid: The puzzle features a standard 9 × 9 layout. This major grid is split into nine standalone rows, nine vertical columns, and nine smaller 3 × 3 zones. [1, 7]
* The Objective: Fill the entire board so that each row, column, and 3 × 3 zone contains nine distinct colours without a single duplicate. [1]
* The Starting Setup: Each puzzle boots up with a fixed set of pre-placed colour blocks. These "clues" are locked into place and cannot be altered or moved, serving as your logical anchor points for the rest of the board. [1, 7, 8]
* Pure Deduction: No mathematical calculations or counting are required. Victory is achieved entirely through the process of elimination, pattern tracking, and careful visual placement. [2, 9, 10, 11, 12]
How to Play & Basic Strategy
Because your brain registers hues differently than it does numbers, the mental approach shifts away from counting to spatial scanning.
1. Isolate a Single Palette: Focus your attention on one specific colour at a time. Trace its pre-existing positions across the board to figure out where its placement is restricted in adjacent zones.
2. Scan the Boundaries: Look for rows, columns, or 3 × 3 sections that are already heavily crowded with colors. The fewer open slots a region has, the easier it is to deduce which remaining shades fit perfectly. [1, 6, 13]
3. Cross-Reference Intersection Points: If a particular cell sits at the intersection of a row and column that collectively display eight of the nine possible variations, that cell's true identity is immediately revealed by the process of elimination. [7, 13]
Key Benefits & Audience Appeal
Codoku alters how the brain processes logical constraints, offering unique advantages over its numerical predecessor:
* Overcoming Math Anxiety: Many individuals shy away from traditional puzzles because numbers feel intimidating. Codoku provides an identical cognitive workout using purely artistic and visual cues.
* Brain Activation: Studies on colour-based puzzle games reveal that tracking vibrant hues activates a broad network across multiple brain lobes. This balances spatial recognition with hard logic.
* Accessibility for All Ages: The visual layout makes the game highly intuitive for children. It acts as an excellent tool for developing early problem-solving skills, and its scale can be adjusted down to a 4 × 4 or 6 × 6 layout for beginners.
* Digital Convenience: Modern digital adaptations feature responsive click-to-select palettes, clear mistake highlighting, and hint mechanisms designed to keep gameplay moving seamlessly without the mess of paper and pencils. [2, 7, 14, 15]
Essential Rules to Remember
* Each color must appear exactly once per horizontal row.
* Each color must appear exactly once per vertical column.
* Each color must appear exactly once per bordered 3 × 3 box.
* Locked starting blocks cannot be modified. [1, 7, 16, 17, 18]
If you want to dive deeper, let me know:
* Would you like tips on designing a physical DIY version using tiles or pegs?
* Are you looking for a python algorithm to automatically solve colour grids?
* Do you want to see how to handle advanced strategies like color-chain linking?
What’s new
Version 1.7.0 · Updated October 22, 2026
Upgrade software infra.
User reviews
Colors are always interesting over the numbers, so if you're a fan of Sudoku, you should try this.
Alternatives to Codoku
Looking for apps like Codoku? Here are 6 similar Android apps on Google Play. The highest rated is Nuts Spinner - Nut Sort Puzzle (4.7/5), and 4 of the 6 are free to download.
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Sudoku Minimal
| App | Rating | Price | Installs | Last updated | Compare |
|---|---|---|---|---|---|
| Codoku | – | Free | 10,000+ | Oct 22, 2026 | |
| What the Hex! Color Sort | 4.5 / 5 | Free | 500,000+ | May 7, 2026 | Compare |
| Slitherlink: Loop the Snake | 4.6 / 5 | Free | 100,000+ | Apr 28, 2026 | Compare |
| Jigsaw Puzzle - Daily Puzzles | 4.1 / 5 | Free | 5,000,000+ | Oct 9, 2026 | Compare |
| Nuts Spinner - Nut Sort Puzzle | 4.7 / 5 | Free | 100,000+ | Aug 21, 2026 | Compare |
| Blue Fish Yokohama | – | 4.49 USD | 10+ | Aug 22, 2026 | Compare |
| Sudoku Minimal | – | 2.49 USD | 500+ | Sep 5, 2026 | Compare |
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