Why are my Clone leaves yellow and stems purple

Cut clones off my White Widow mother plant, Put them in the clonex rooting gel, soaked the rockwools and placed the clones in the rockwools then places them in their dome. For the next 7 days I took off the lid for 5-10 minutes and lightly misted them, on the 6th day the stems started turning purple and the leaves started turning yellow, on the 7th day opened the vent holes 1/4 of the way, on the 9th day opened them 1/2, on the 10th fully opened, on the 12th day took the dome off and gave them a light dip into clonex solution/feeding and put them back in the tray.

My question is why are the leaves turning yellow and the stems turning purple?

Plant use quite a bit of Phos. during the rooting process and the purpling of the stems and the yellowing of the leaves are signs of that.

Clones are one thing I don't really know about. But they don't look too terribly purple.

I've had seedlings turn purple and stunt for a week before resuming growth. That was a temperature thing for me though.

why the paper still on rockwool cubes...

That is usually a good sign as far as the leaves turing yellow it means the plant is active and in search for food so it will start to use what is in the leaves. At the same time that would also indicate you have roots I assume you do but can't tell from the pictures just a light feed like you did already and watch the new growth thats all you can pretty much do same goes for the purple stems.

That's normal for clones.