I've been having a bit of a play recently with Sudoku (generators, solvers and puzzles). It's all the rage, after all. While I was at it I came up with what I believe is a new type of Sudoku puzzle - colour sudoku. There's an example below,
I'll be releasing a Colour Sudoku site in the near future (once I get hosting figured out)
To play, you must fill all columns and rows with the digits 1-9. Each digit can only appear once in each column and row. Additionally, you must fill each set of nine identically-coloured squares with the digits 1-9. Good luck!