Yellow leaves on some buds

What @Ultraviolet said

That's normal, at the end of the cycle to see yellow and autumn colour leaves especially when your flowers look so close to the end I'd be checking trichomes and packing a flush soon

Microorganisms use nitrogen to convert carbon to sugars, once carbon nitrogen ratio reaches a point.the plant will begin dumping its nitrogen to feed the micros. Senescence.

Probably due to switching to bloom nutrients too early, otherwise it really isn't an issue this late in flowering.

Totally normal late-flower fade, The yellowing on sugar leaves close to the buds just means the plant is pulling out the last stored nutrients a good sign she’s nearing the finish line. As long as the buds themselves aren’t drying or crisping, you’re golden. Just keep an eye on trichomes and let her finish strong

Those nugs are almost done.. welcome those fall colors with a smile grower!

Looks like lack of nitrogen prob a ph problem also don’t worry to much your plant is almost done

Looks like senescence to me? Diary would help.

Sure looks like N-def but that should start at the bottom, though i do see some very yellow leaves down below... didn't you have a question not long ago and applying too much light? The reddish bits are probably cold temps at night or genetics. Anything at or below 68F can potentially cause some Autumn leaf colors. Some genetics just do it, too. This isn't too much of a concern. don't let it drop below 18C and you'll be fine.. think thats ~65F? The problem with learning factoids in imperail vs metric, lol... get a mix in the memories. you can look at a marijuana leaf symptom chart as well as anyone else... you also have more intimate information beyond these pictures, so you can rule things out. Do a google image search and get something you can reference. Keep asking questions, but also try to do it yourself.. work through what the symptoms are, where they atarted and how they progressed. Leaf symptoms themselves are not discrete. They are not enough on their own to confidently diagnose most deficiencies or toxicities. Many have a lot of overlapping symptoms. Mulder's chart is also a useful visual aid to have around when trying to diagnose. It displays the likely antagonism/stimulation between nutrients. What is most likely to lock something else out etc... Tracking your fertilization per nutrient (n,p,k, et al), especially in a soills/hydro context, can really help. In a soilless/hydro context it makes it super easy if you track this stuff. As you play around with formula, you'll learn upper/lower thresholds relative to your ratio of nutes used (goes back to mulder's chart as to why). YMMV if your ratios are quite a bit different from someone else... while there is definitely a more optimal way, there are many ways to skin this cat and get healthy plants... some formulas will work on a wider range of plants and some may improve growth rates by comparison... good luck figuring that out and make sure to tell everyone else :P N-deficiency is an easy one -- pales tip-in on leaft and bottom-up on plant. Nothing else does it in that way, but that is an exception to the norm. If a light is too intense, it could cause symptoms near top even if it is a mobile nutrient (this is not a binary term.. there is a spectrum of mobility, but the stuff that starts near the top is less mobile... one way to differentiate some symptoms but again.. too much light can cause oddities or a problem in root zone may look like something but start in an odd spot etc etc) Start doing it... until it gets comfortable... you'll want to trust your perceptions because you have more info at your fingertips.

Die Pflanze geht an ihre Reserven in den Blättern weil zu wenig Nährstoffe durch das Gießen kommen.

NPK def