Disjoint Groups Sudoku

Disjoint Group Sudoku (Offset Sudoku) is a logic puzzle. This Sudoku variant contains an additional nine groups of nine cells each.

Rules: In each cell of the NxN grid, enter a number in the range 1–N. Each number must appear exactly once in each row, column, and block.
Additional rules: No number can be placed in the same position in any two 3×3 blocks. In other words, each number must appear exactly once on the cells of the same colour.