PLEASE READ ALL OF THIS BEFORE YOU START THIS PUZZLE!!

Here is my first mystery cache. I honestly never thought I could make my own, because the ones I've seen have been pretty complex and extremely well thought out (PhilNi comes to mind...), but here I am. I am an avid sudoku player, and I figured if I'm going to make a mystery, why not do something I know well? If you don't know how to play, it's actually extremely simple to pick up, you can just look up "how to's" on YouTube and you'll find some walkthroughs. If you do know, this particular puzzle is labelled "expert" and "difficult" on different pages, so good luck and stay with it. As for the endgoal of this puzzle, you are looking for the three numbers that are in rainbow order: red, green, then blue (if you're colorblind, it's {column 2 row 1},{column 8 row 5}, then {column 3 row 3}).

Now that you have these 3 numbers, it's time to discuss the hide. The coordinates are actually correct for the final; the catch is, the logbook is guarded by a combo lock that you need to crack. By now, you can probably assume to use the 3 numbers, in order, to open the cache. I should also mention it's a clear preform tube. The location (as of now) is indeed in front of a house, but you should not need to take your feet off the dirt. If you look like you're geocaching we'll know, but if you message me before you start your find, you would receive extra brownie points. Also please drive slow in this neighborhood as there are lots of children and dogs out and about, rain or shine!!!

If you want to check your answer, feel free. If you want the thrill of testing it in person, also feel free. You can start the puzzle now, optional reading is at the bottom.

My grandpa had either a lucky number or a favorite number, maybe it was both. It popped up throughout his life, and my dad inherited it. My understanding is he didn't know his dad had the same number, which is bizarre to think about. I knew it would show up in the weirdest places for my dad, which I saw as frequent acts of synchronicity. My grandpa passed away from AML last June, perfectly peacefully, so don't feel obligated to say anything in the logs. Ever since that trip back to see him before he went, the same number has been following me. Every time I see it I get so freaked out, but now I also think of it as my grandpa saying hi. This story is why this cache is named how it is, and I just knew I would have to incorporate this number in this combo lock somehow. After all, what other number would I use?

You can validate your puzzle solution with certitude.