I had exactly the same colors developing in my plants when I was running in DWC. Turned out that my PH was well out of whack. I have since transported to peat substrate, recallobrated my ph meter, flushed them with PH corrected water and gave them a lower doses of nutrients on the next feed. I also added a little CalGel. Took about 10 days until I saw that the new leaves were growing nice colors again, although the old leaves still showed the same problems.