I’m kinda color-blind, help me pick a deficiency please...

I use RO water for RDWC and you def need to supplement CalMg! To me that does look like calmg but sometimes it may be a PH problem. Like you I cannot see all colours properly, I had to buy a digital PH meter cause I couldn't read the colours of the water. That was a lifesaver for me and a PPM meter, keep both calibrated. Likely those leaves with the spots and stuff will not ever look better but its newer growth that will be nice once you balance things out. I have read that PH readings without some sort of particulate "CalMg"using RO will have a false reading because there isn't anything to be measured. I use CalMg at 3-6ml per gallon plus nutes, PH then add PH stabilizer/Cleaner "Z9". Just wanted to share some of what I have learned. :P