Hard technique
How to Find Hidden Pairs
When two colors can only go in the same two cells, those two cells belong to them. Remove every other color from those two cells.
1
Read the block
BEFORE
This block has seven open cells, and none of them shows a single color, so nothing can be placed yet. Pick one color at a time and find every cell in the block that shows it.
2
Find two colors in two cells
Red and Orange only appear in the bottom left and bottom right cells of this block. Two colors, two cells. Those two cells must hold Red and Orange.
3
Remove the other colors
Those two cells are taken, so no other color can go in them. Light Purple comes off the bottom left. Yellow and Dark Purple come off the bottom right.
4
Place the color with one place left
AFTER
Yellow now shows in only one cell of the block: the middle right. A color with only one place left must go there, so place it. The two bottom cells are still undecided, and that is fine.
Cells being readKey cellColor tints match the color being followed
Key Insight
Follow colors, not cells. Pick a color and see where it appears in the block. When two colors appear only in the same two cells, you have found a hidden pair. It works the same way in a row or a column.
Related Techniques
Obvious PairsThe same pattern found from the other side: two cells that show only the same two colors. It clears those colors from the cells around them.Hidden TriplesThe same idea with three colors and three cells.If you’re stuck on a puzzle, see what to try next, in order.