Leaf Discolation

[OldManGrower]

I am at a loss to figure out this issue. Late in their life cycle, some of my plants are turning lime green all over and then yellow. This is not bottom to top but the whole plant. Some of the leaves are developing a purple "barred" appearance. This has developed on two different strains. The trichomes are mostly milky with some clear and no amber. I had to harvest one plant, a gorilla glue auto as all the leaves were yellow and I was afraid to wait any longer.
My PH both in and out has been in the mid 6 range through out their growth.
At this stage I water about every four days with three gallons of water for the five (now four) plants and have about 15% runoff.
I am using GH three part nutes at about 3/4 strength along with cal-mag at about 1.5 teaspoon per gallon. Also molasses at about two tablespoons per watering.
The plants are in 5 gallon pots except for one three gallon. The soil is a mixture of 1/3 used mushroom bedding, 1/3 top quality garden topsoil with no added nutes and 1/3 previously use soil.
additives are dolomite lime and pelletized Sulphur with some perlite.

 

[OldManGrower]

For some reason my pics did not come out. Lets try again

 

[dphipps1020]

I could be wrong and can't really tell from the lighting, but they look fine to me. Looks like it's mostly the little leaves where the light doesn't quite reach, along with natural yellowing. Maybe a little light on N, might up that a little bit. I also just looked at your pH, I would maybe increase that to around 6.5-7.

 

[JohnEmad]

I agree with dphipps1020,
Plants look ok to me and ph could be a bit higher.
The purple color can be from strain type and/or cooler nights.
Can't be long till harvest although waiting for that amber can seem to take forever sometimes.

 

[dilvish]

when the plant starts yellowing all over at late stage bloom it just means the plant is using up all the remaining nutrients. It's normal. i would just let them go now and just water with plain PH'd water for the next week or 2.

 

[OldManGrower]

Hey thanks guys! I appreciate your comments and assurances. I knew the plant would yellow as it came close to harvest but never anticipated just how fast it could occur. Never had that happen, nor the purple barred leaves on any of my previous grows. For anyone interested, the temp in my tent is usually in the 68-73 degree range. Although I am an experienced grower, a second opinion never hurts and as per usual, I learned something.