I made the right 4 number guess in the 8th row and got it the first time!
Hoo boy, only six and already stuck.
Interesting stuff, but too deep for my little brain right now. There may be a pair chain I can exploit without greens when I can think more clearly.
Did it, no green, one nap, three wrong guesses. As usual, the more productive looking guess was always the "wrong" guess, which I put in quotes because it's easier if I can eliminate a wrong guess without making a tree of guesses.