Simple coloring: wrap

A worked example

This position comes from SudokuByte’s lesson on the Simple coloring: wrap. Gold cells hold the evidence; green cells are the pattern’s ends.

1. Where to look

   Look for a repeated color in one row, column, or box.

   If two same-colored candidates conflict, that color cannot be true anywhere in this connected component.

2. Read the evidence in this position

   For digit 7, connected strong links produce two alternating groups. Teal: r7c1, r8c2. Gold: r7c2.

3. Why the deduction must follow

   r7c1, r8c2 have the same color but see one another. They cannot both be 7; therefore that color is false throughout this connected component. Remove every candidate of that color.

4. Apply the result

   Erase 7 from r7c1, r8c2. The pattern may remove candidates without immediately solving a cell.