Yellow clone leaves

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?

did you soak the rockwool cubes first then put gel in ,rockwool doesnt dry up hardly at all ,what i do is mix clone tek in my water then soak cubes overnight,then put gel in hole then dip clone in gel place clone in rock wool ,i think you might be over watering them,by 10 days you should have roots ,try to pull 1 of the cubes apart to see if you have rotted them.
again you should have roots by now,i also just keep a little light on them ,i have found they dont like strong lighting as clones,that is just my experience,the purple stems could be that they are cold or it could be the strain.
when you feed are you still using the clonex ,i use 3ml to a gallon of ro water,again that is just me,maybe these ideas will help ,i hope i touched something for you,hang in there someone else will have other ideas and you will have to decide which route to take ,honestly i think you are just over watering and they have started to rot ,you also didnt mention if you have them on any heat source ,so cold and overwatered,hope this helps happy growing to you

^definitley on the right path...
Ive had strains that are fussy to clone...they most likely need a heat mat to help them along. Dont mist, your dome should create enough humidity inside

Those don't look like their gonna root

Experiment cloning different ways until you find something that works for you. Good luck