LogFAQs > #962438364

Serious Cat posted...

After reading that, my apparently needlessly complicated set-making tells me that every number in the grid appears diagonally adjacent to itself everywhere it appears in the grid unless it's in the center of a block. Unless I'm mistaken.

This appears to be right, but speaking of your needlessly complicated set-making skills :P I think you are still being more clever than is necessary. At the point I showed you can just start simplifying colors:

Look at the 6-boxes: The top-right one, for example, has 4 cells that have 4 options, (yellow, blue, green, light-grey) and as a result the remaining 2 cells cannot be any of those 4 (can't be green or light grey), thus you know it's a purple/mid-grey pair, and from that you can start eliminating purple/mid-grey from it's column and from places where sudoku+knight's move sees both those cells. You can do the same thing in low-left 6-box and get the cells in C2 to be a yellow/purple pair.

I've noticed none of your pictures have had multi-color on, are you not using that? If so that will make things very hard.

Once you know the break-in all that's left is color the grid fully, use the 6-boxes and start simplifying until all colors are resolved.