leafs turning yellow on cuttings

Im having some problem with my cutting, the leafs on them are all turning yellow they havent taken roots yet and i keep them in a plastic box under a 125w envirolite bulb witch i have just above the box maybe 10 cm above...
I also try too keep as most moisture as i can in the box while the cuttings are taking roots so i spray them about 3 times a day maybe thats my problem? too much moisture? or too much light ( witch is on 24/7 ).
Im using all the right nutes and root stimulators for them....

i find that the cuttings that start to yellow are the first to grow roots, i had the same thing and first i thought they were dying but it was the green ones that never took hold

hmm... ok thats strange but u might be right cuz the healthiest cutting are the most yellow ones but im not sure i thought it was because of to much moisture or light