Spectradoku 4X4
(Published on 21. July 2026, 10:08 by Todd)
Fill every cell of the 4×4 grid with a digit 1–4 AND one of four colours (red, yellow, blue, green) such that:
- Each row, column and 2×2 box contains each digit 1–4 exactly once.
- Each row, column and 2×2 box contains each of the four colours exactly once.
- Each (digit, colour) pair appears exactly once in the whole grid — there are exactly 16 distinct pairs (e.g. only one red 1, only one blue 3, and so on).
Solution code: Row 4 — the four digits first, then the four colours (r=1, y=2, b=3, g=4). Eight digits total.
This is the introductory variant of Spectradoku (Double Orthogonal Latin Square Sudoku). The full 9×9 version is free to play at spectradoku.com. Related puzzle: 000TJW.
Solution code: Solution code: Row 4 — digits first, then colours (r=1, y=2, b=3, g=4).
Comments
on 23. July 2026, 06:59 by Todd
@WasabiKoala Thank you so much! I'm super happy to hear it clicked with you :D This 4×4 is meant to be a low-stakes taster of how Spectradoku mechanics work — if you want more, come find the 9×9 version on the website https://spectradoku.com (the full game on Steam will come later this year with more puzzles, from tutorial to master)
on 22. July 2026, 11:41 by WasabiKoala
I really enjoyed it! It's a fresh way of thinking that touches something in my brain, and I like it ^^
on 21. July 2026, 12:57 by AshBrown
How do i play it? Ok its number 10 on the tutorials.
