You don't have long to go. A little fade is good. It means you didn't overfeed like crazy and your leaves are still photosnythesizing, if that's a correct conjugation of that word, lol.
Looks awesome. Beginnig of amber triches.. guess 5-10 days? I wouldn't worry about the lower leaves.. maybe start your normal flush slightly later (i'm not a fan of flushing, but a few days is good.. maybe ~5-7 in soil in your context... 14 days is great for those that bomb the heck outa their plant with nutes from day 1, methinks.. but trial and error is 100% neccessary on these topics in anyone's specific garden.)