Logic Masters Deutschland e.V.

This puzzle might be on the harder side of the spectrum, so I wrote a walkthrough guide. Please give it a good try before looking and let me know in the comments what you think. Does it spoil the fun or should I write hints section to all of my harder puzzles?

Rules

Normal Sudoku Rules apply. Cells a chess knight's move apart cannot contain the same digit. Digits in a cage cannot repeat and each cage must sum to a unique total. White diamonds joins cages with consecutive sums. Black dots join digits in a 1:2 ratio.

Play this puzzle on CtC web app

Walkthrough

1. There's 9 cages and all have 8 cells, thus for every digit 1-9, there must be exactly one cage missing the digit. The 9 cells outside any cages must form complete set 1-9.
2. Best place to start colouring is R1C1. You may use any colour, but for this walkthrough lets name it with letter A. It should be obvious which cage is missing A, so all the other cages must contain A. You should be able to correctly place it in boxes 2, 3 and 6. In boxes 4, 5 and 8 there's only two options.
3. Next cell for colouring is R2C4 (letter B). Two possible places in boxes 5, 8 and 6. Only one option in box 3. In box 8 there's now AB pair. You could also do some work in boxes 1, 4 and 7 if you chase around the grid, but we don't need that yet.
4. This is the first tricky part. R2C6 sees 7 cells outside cages and digit A is already placed in the box 2, so R2C6 must be same as R8C3 (letter C). In box 3 there's only one option for C and in box 5 we get BC pair.
5. R2C7 (letter D) and R4C5 (letter E). Column 6 has only two places left, so we get DE pair in box 2. In box 5, D has only one valid place, so it resolves A in boxes 4 and 5. One of cages on the right side of the grid is missing D, so every other cage must contain D. (Four options in box 7, 2 options in box 4, etc) Also note that E is missing from the central cage, so all the remaining digits F-I must appear in it.
6. R7C6 (letter F). There's only one possible place left in box 5. Next deduction might be hardest in the whole puzzle: F can't be placed in R3C7. Just chase around the whole grid and you should get a contradiction.
7. If you haven't done so yet, make sure all possible options for the first 6 colours are marked in boxes 3-6. There should be 3 uncoloured cells in row 5. Also R3C7 (letter G) is uncoloured, so it must be same as R5C3. You should now be able to place G in all the boxes. Also the two uncoloured cells in row 5 now form a pair, so R5C2 is naked single E and R5C9 is naked single D.
8. R6C6 (letter H) can be placed in box 6 and forms a pair in box 8 with D. R5C6 (letter I) forms a pair with H in box 2. There's still some work to be done, but if you made it this far, it should be relatively easy, mostly basic sudoku stuff. When the colouring is almost finished, there should still be an unresolved DH pair in boxes 7 and 8. Luckily one of the cells has black kropki dot.
9. For the final part of the puzzle, you should note for each cage which colour is missing from them. If you used letters, you could use corner marks. E.g. corner mark A in the cell R2C1. If two cages have consecutive sum, the digits missing from them must also be consecutive.
10. There's a chain 5 cages joined by 4 white diamonds. Exactly two of the digits missing from them appear on a black kropki dot and they are consecutive. So they must be chosen from 1234. Their counter parts on black kropki dot does appear on all of these five cages, so neither of them is part of this set of 5 consecutive digits. There's only one way to do it and you get first five digits mapped to colors.
11. You get one more digit directly from kropki dot. For the remaining three digits you must use the last white diamond. This will also disambiguate DH pair in boxes 7 and 8.