Variegation. Little inconsistency in pigmentation on first couple sets of leaves is nothing to worry about.
Up-potting autoflowers does not shock them. I've yet to see a plant shocked from up-potting in 5 years and multiple hundreds of up-pots.
It's nearly impossible to water them properly when they are not drinking fast enough to warrant the pot size. Water a small column (slowly expand as it grows larger) around the plant, but you need to make sure the wetness goes all the way down to the botom, which means it'll sperad out to nearly the width of the pot anyway. This means it'll stay wet for a longer period of time than what is healthy = higher risks. If you don't water to the bottom, you train the roots to grow superfically which is even worse.
so much easier to just use a properly sized pot and not fall for the urban myth that up-potting is dangerous and will shock many plants... simply doesn't happen. All you should be doing is gently placing a rootball into soem soil and gently covering it up... if you agitate and man-handle the rootball, that's a self-inflicted problem easily avoided. Even then, good chance you don't see any shock, lol.
always give the volume of water required to do the job correctly and not some volume you whimisically picked out of your imagination. If you water at same loss of weight, it'll take the same volume of water.
read the guides on cocoforcannabis.com. watch bruce bugbee videos. Avoid bro-science. if it sounds like a bad supplement commercial, it's 'bro science' - promises the world and vaguely explains in some nonsense way or even attempt to sound science-y.