# Coloring Sudoku Squares [Page 11 of 15])

To keep track of squares on paper and pencil is easy, you can mark a square and rub it out when no longer needed. Sudoku Dragon offers color marking that lets you easily put a temporary mark on a square. There is a command to quickly clear coloring from all squares in one go.

The colors are added from the right mouse menu or the **Edit** menu or, using the keyboard **SHIFT+Function key**.

In this example puzzle screenshot, coloring has been used to identify squares that can take a **5**. Alternate pairs have been marked with different square colors.
Starting with orange square **Bg** this is paired to turquoise square **Hg**. Only one of these two squares can be the '5' in column **g**. Next **Hg** is paired to orange square **Ii** as a pair in region **Gg**. This square is in turn paired with turquoise square **If**. In addition there is another pair **Bd** (blue) and **Fd** (red) in column **d**. Having marked the alternate pairs it is evident that square **Bf** (lime green) can not take a **5** as it is in the same column as a turquoise square and the same row as an orange square. If the orange squares are correct then **Bf** can not take a **5** but nor can it if the turquoise squares are correct. As either orange or turquoise must be correct and not both must be correct that proves it!

You can use coloring just to remember particular interesting squares. Together with the square annotations coloring is a useful feature.

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One of the very few Sudoku solvers that gives you color marking.

- Tour Guide
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- Puzzle solution hints
- Annotating squares
- Explaining possibilities
- Showing possible square assignments
- Possibility display control
- Automatically solve 'easy' squares
**Coloring squares**- Large Sudoku puzzles
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- Puzzle display skins

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