@Roy Looks like micro nutrient deficency, possibly Iron, maganese or Zinc
could be caused by lockout and excess of other nutrients show some pics of rest of plant
Have you tried feeding more to solve this?
or are they hungry?
Could be that you are overfeeding
What have you given them so far
give us some background
I boosted the amount of microblast they we’re getting. Newer leaves coming in darker. Was first time trying mother of all bloom in first week of bud to induce flowering
If you are following these micro blast instructions:-
“Use 1-2 tsp Microblast per gallon of water, every 2 to 4 weeks”
I doubt thats the problem.
MOAB is probably your problem
“Combine 1-2 teaspoons of M.O.A.B. per 5 gallons of feed water. The amount of base nutrients may need to be reduced by as much as 50% when using M.O.A.B., over feeding may burn plants.”
Did you try reducing your main feed by 50% (or more)?
Ive never used either of these products but MOAB is just a PK boost which will easily overfeed Phosphorous & Potassium.
Thus locking out all the micronutrients
Flush with weak flower nutrient and dont use the MOAB until later and then sparingly
Personally I dont use flower nutes till the 2 week of 12/12 as they need N for stretch
I didn’t reduce nutrients, damn. Was still feeding vegetation nutrients as well as M.o.a.b. the top leaves are coming in normal now, but still some lower ones are banded( I think thats the term)
the old ones will be like that forever, more than likely
as long as new growth is ok its all good.
Glad you got em sorted 
Strange characteristics. The first pic really does look like physical damage as noted by Muleskinner. It’s possible to poison a plant with too much nutrients just as easy as discoloration caused by low nutrients. People always like to use the term “lock out,” but are you sure this a possibility? The greater tendency from what I’ve seen of these forums, is for people to feed too much. Whether this causes the dreaded lock out seems less likely than poisoning the plant with too much stuff. The thing to do is use a super soil medium, premixed and aged for a couple months to avoid any nutrient problems. The more we add and try to control the nutrients, the more trouble we get into. With super soil, if the plant needs more nutrients you just up pot to a bigger size and more soil. In the end, I don’t know what is causing these problems but hopefully people learn to control the grow less because doing so seems to be a losing game, unless you know what you’re doing.
I do want to mention that the first pic looks like a genetically-based damage failure to develop the tissue that is normal.
Was done on the advise of a friend to reduce growth during the first week of bud. Probably won’t be doing that again.
Transplanted into larger pots and been giving straight water. Maybe a dozen leaves miscolored is all, the rest turned back to normal. Completely root bound, might have added to the problem
i always double-check mynamestich’s guide here first, then 
how far along are they? (looks like veg/pre-flower)
i’m unfamiliar with the products, but i know:
over dose on microbes = bye bye nutes!
and
certain nutrient excesses lock out/make unavailable others.
is this hydro/soil/combo?
and of course… pH says “what?”
c.s