Only One Colour Per Line
A colour-logic puzzle where each colour may appear only once along every line of the grid.
Controls
Click or tap a cell to set its colour, cycling through the available colours as you go.
How to Play
Only One Colour Per Line borrows the spirit of sudoku but plays with colour instead of numbers. You are given a grid to fill in, and the single guiding rule is that the same colour may be placed only once on any given line. Break that rule and the line is wrong, so every placement has to respect what is already sitting alongside it.
Solving comes down to reading each line and eliminating colours that already appear, until only one option remains for a cell. It is a quick, tidy logic exercise: no arithmetic, just careful looking and a bit of forward planning.
Tips & Tricks
- Start with lines that are nearly complete, where only one colour can legally remain.
- Scan across a cell in every direction before you commit its colour.
- If a line stalls you, solve a crossing line first to remove one of its options.
Frequently Asked Questions
What is the core rule?
A colour can be used only once per line. Fill the grid so that no line repeats any colour, in the same spirit as sudoku but with colours in place of numbers.
Do I need any maths to play?
None at all. The puzzle is purely visual logic: you match and eliminate colours rather than working with numbers.
