What do the leaves indicate

Yes, magnesium deficiency.

calcium and magneisum are 2 different things. they can't even bond directly together as they are both positively charged elements. I don't use any "cal-mag" product because i have calcium nitrate and magnesium sulfate in my ingredients. never used a calmag product, ever. but it's so popular people mash these 2 different elements together.. but this is erroneous. I think maybe your light is playing a trick on you. The leaves look full / plump and i think it's a shadow/illusion as far as athe discoloration. Think they are just really flush with water. gently flatten a leaf, even use soem regular lighting with grow light off while you do it.. bet it;s more of a solid color than it looks in pics. interveinal chlorosis, if not an illusion, without spots (if they don't form later but not wouldn't take much progression for it to be seen) is not Mg-related. Calcium deficiency does not cause interveinal chlorosis. Another tidbit about magnesium -- a deficiency starts 30-35+ days before you see any symptoms. So anytime you are looking at a young plant, usually safe to assume what you see is not magnesium related. anyway, more than a few things cause interveinal chlorosis without spots.. you'd need to consider how much you've fed of various needed molecules an dmake an educated guess armed with better information. Refer to any leaf symptom chart for the list of various things that can cause interveinal chlorosis.. i'm wagering at least 5-6 do, so no help looking it up and referencing 6 things here...