A 9x9 board rated fiendish, level 275 of 300. Catdoku levels are identical for every player, so this solution always matches the board in your game.
The level 275 board
Place one cat in every row, every column and every colored patch. No two cats may touch, not even diagonally.
Level 275 answer
Row 1: column 4, in the yellow patch
Row 2: column 9, in the sky patch
Row 3: column 6, in the rose patch
Row 4: column 8, in the mint patch
Row 5: column 1, in the lilac patch
Row 6: column 7, in the peach patch
Row 7: column 2, in the aqua patch
Row 8: column 5, in the coral patch
Row 9: column 3, in the lime patch
How to solve level 275, 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 9: the coral patch is down to a single free square at row 8, column 5, so its cat settles there.
Every free square of the lime patch sits in row 9, so the lime cat must come from there and the rest of row 9 can be crossed out. Column 6 only has free squares inside the rose patch, so that patch's cat is spoken for and its squares outside the line can be crossed out. A cat at row 1, column 2 would leave the yellow patch with no home for its cat, so cross that square out. A cat at row 6, column 1 would leave column 2 with no home for its cat, so cross that square out. A cat at row 6, column 2 would leave column 1 with no home for its cat, so cross that square out. The yellow and sky patches all squeeze into rows 1 and 2, so those rows are reserved for them; every other square there can be crossed out. A cat at row 4, column 3 would leave column 2 with no home for its cat, so cross that square out. The sky, mint and peach patches all squeeze into columns 7, 8 and 9, so those columns are reserved for them; every other square there can be crossed out. Cat 2 of 9: the lime patch is down to a single free square at row 9, column 3, so its cat settles there.
Cat 3 of 9: the yellow patch is down to a single free square at row 1, column 4, so its cat settles there.
Cat 4 of 9: the sky patch is down to a single free square at row 2, column 9, so its cat settles there.
Cat 5 of 9: the mint patch is down to a single free square at row 4, column 8, so its cat settles there.
A cat at row 5, column 6 would leave row 6 with no home for its cat, so cross that square out. A cat at row 3, column 2 would leave row 5 with no home for its cat, so cross that square out. Every free square of the lilac patch sits in column 1, so the lilac cat must come from there and the rest of column 1 can be crossed out. A cat at row 6, column 6 would leave column 7 with no home for its cat, so cross that square out. Cat 6 of 9: the rose patch is down to a single free square at row 3, column 6, so its cat settles there.
Cat 7 of 9: the lilac patch is down to a single free square at row 5, column 1, so its cat settles there.
Cat 8 of 9: the aqua patch is down to a single free square at row 7, column 2, so its cat settles there.
Cat 9 of 9: the peach patch is down to a single free square at row 6, column 7, so its cat settles there.