Puzzle Creator here: I have solved the puzzle twice to make sure it's logical, however you will likely need to use some advanced logic here. If you need to use temps, it's best to start at the top row. The two-star difficulty level is deceiving.
Completely logical, no temporaries needed. Only a bit of "2-D logic". More like a 3-star difficulty, but not one of the hardest puzzles I've completed... not by a long shot.
Image looks like a nut and bolt. Thanks!!
unnecessary hint : C1R15 is black, I had to use temp for this one but I guess it can be found out by a little more advanced logic or something.