Looking at the 9 in box 5, the light greens are possible 3s and the light blues are possible 5s.
There are at most 4 possible 3s, which means we need at least 5 5s.
Box 6, 8 and 9 between them can give at most 2 5s. Which means we need at least 3 5s from boxes 2, 3, 4 and 8 - if we can elliminate even one of those as possible, it fixes a lot...
Looking at the red 6 diamond in box 1, it can have 2 fizz at most, meaning it needs at least 4 buzz. Which it can potentiall get from boxes 2, 3, 4, 5 or 7 - so, again, elliminate one of those possibilities and we're sorted.
I've put circles around the key squares I'm interested in elliminating:
I've noted that r4c5 and r4c6 are the only possible locations of a 3 in box 5. And that r9c5 and r9c6 are the only possible locations of a 3 in box 8. Therefore, either 2 of them hit the 9 or neither of them do. And if neither do then there are not enough 5s able to hit the 9. So it MUST be 3s in r4c5 and r9c6:
Looking at the 7 diamond in box 1, there are certainly at least 2 and no more than 3 threes hitting it, meaning there are 4 or 5 5s hitting it. If they come from boxes 4 or 8 they can only come from the circled light blues in those boxes, which even it none of them get elliminated still leaves 2 or 3 to come from boxes: 2, 3, 4, 5 where they'd have to come either from the light blue circle in box 3 or from one of the cells I've circled in red:
Looking at the blue 2 in box 9, we note that 3 of the 4 red circled 5s hit it, meaning one of them can't be a five. So, to complete the 7 in box 1 the only way for the red circled 5 in box 2 not to be needed would be if there were 3 3s on the 7 in box 1, which would require the 3 in box one to be in r2c1 but that, in turn, would leave the green 1 diamond in box 1 without a 3 pointing at it.
SO, THEREFORE:
r1c5 _is_ a 5.
From there we have several routes. We can do more jiggery pokery with the 2 and the 4 in box 9. But perhaps the easier path is to use standard sudoku naked and hidden singles, which takes us to: