I had something like this happen within the past couple days. I just left it hoping it would turn green again. The plants shot out new growth and the "white" leaves turned yellow, so I trimmed them. Not sure what it means, but mine are back on track, looking as good as ever. I'm using an led full spectrum light for the first time so maybe it has to do with lighting. I also didn't water them over the weekend, so that might be a possible cause.
maybe ill have to get magnifier out. Cheers man. just starting it for someone he potted it usin my light for now an i been occupied wi my baby lol. thanks for your time anyway ill keep my eye out for insects. peace,
and a pic of my healthy one lol, im so proud haha