Ready to put Simple Coloring into action? This page is designed for you to practice and master Simple Coloring with positions from real Sudoku puzzles.
Every board above is a position from a real puzzle where the Simple Coloring is the next step. Tap the candidates it removes (or select a cell and press the digit) and press Check. If you’re stuck, Show me gives the answer and Next puzzle loads another. Want to watch one first? Switch to Worked example.
Quick Reminder: What is Simple Coloring?
Simple Coloring follows one digit through its conjugate pairs (houses where it has exactly two places), giving the two ends of each pair opposite colours. If a cell sees both colours, it can lose the digit. If one colour ends up twice in a house, that colour is false everywhere.
Want a full step-by-step guide? Read the Simple Coloring technique article
How to Practice
- Pick a digit and colour its conjugate pairs in two alternating colours, following the chain as far as it goes.
- Remove the digit from cells that see both colours (or from every cell of a colour that appears twice in a house).
- On the board, tap each of those candidates to remove it.
- Press Check. On your first try you see how many you found; on the second, the ones you missed get a dashed ring.
Start Practicing on Full Puzzles
Once you can find the Simple Coloring on most boards without pressing Show me, take it into a full game. Evil puzzles are where this technique starts to come up, and the step-by-step solver will name the technique each time you get stuck.