A 6x6 board rated tricky, level 55 of 300. Catdoku levels are identical for every player, so this solution always matches the board in your game.
The level 55 board
Place one cat in every row, every column and every colored patch. No two cats may touch, not even diagonally.
Level 55 answer
Row 1: column 5, in the yellow patch
Row 2: column 1, in the sky patch
Row 3: column 4, in the rose patch
Row 4: column 2, in the mint patch
Row 5: column 6, in the lilac patch
Row 6: column 3, in the peach patch
How to solve level 55, step by step
After every placed cat, cross out the rest of its row, its column, its patch and the four corner squares around it. The steps below assume you do (the in-game auto-paws assist does it for you).
Cat 1 of 6: the yellow patch is down to a single free square at row 1, column 5, so its cat settles there.
A cat at row 2, column 2 would leave the sky patch with no home for its cat, so cross that square out. A cat at row 3, column 1 would leave the mint patch with no home for its cat, so cross that square out. A cat at row 2, column 3 would leave the sky patch with no home for its cat, so cross that square out. Cat 2 of 6: the only free square left in row 2 is column 1, so the cat goes there.
Cat 3 of 6: the mint patch is down to a single free square at row 4, column 2, so its cat settles there.
Cat 4 of 6: the rose patch is down to a single free square at row 3, column 4, so its cat settles there.
Cat 5 of 6: the peach patch is down to a single free square at row 6, column 3, so its cat settles there.
Cat 6 of 6: the lilac patch is down to a single free square at row 5, column 6, so its cat settles there.