Fill the 9×9 grid so that every row, every column, and every 3×3 box contains:
In addition, every digit+colour pair appears exactly once in the whole 81-cell grid — there is exactly one red 3, one violet 8, etc. This orthogonal-Latin-square constraint is the classical Euler 36-Officers problem generalised to 9×9.
Given clues carry both a digit and a colour (shown as coloured cells with a digit inside).
Lösungscode: Solution code: row 5, digits only, then row 5, colour letters
(concatenated, no spaces).
Example: if row 5 reads
7A 3O 5V 4B 9K 2G 6I 1Y 8R,
the code is 735492618AOVBKGIYR.
am 3. Juli 2026, 03:16 Uhr von Todd
change picture
am 2. Juli 2026, 15:08 Uhr von Todd
Hi! The site currently supports **Smart Notes mode**, which automatically marks the candidate numbers and candidate
colors in each cell — you can also use the eraser to manually clear candidates. **Manual marking of candidate numbers
and colors is still under development.
am 2. Juli 2026, 13:45 Uhr von PierreTombal
The spectradoku tool may need some getting used to, but I don't like it. Being able to mark multiple colours in a cell would be a big improvement.
am 2. Juli 2026, 11:41 Uhr von Todd
If you wanna solve this puzzle online, visit https://spectradoku.com and choose expert #80 to do it, it's very convinient. Thanks!