Difficulty score 56. Followed UTH's example and took a nap. It worked.
That was a deceptive puzzle. It looked hard so I filled in the green. It still looked hard, but the first little trick I tried broke it wide open.
Did it, no green, one nap, one guess. After confirming that was the wrong guess, I found a combo unique rectangle and bent unique rectangle involving the same numbers together; that eliminated two cells and I was able to finish.
If you are interested and don't fault me for giving it away, the unique rectangle, bent unique rectangle combo were like this:
( , ) (1,3) ..... (1,3)
( , ) (9).........(1,3)
So for two different reasons, neither of those empty cells could be a 1 or a 3.