Reddening Protocorms in Replate Flask?

[Royal]

I know someone here can help. I have some protocorms with about two leaves, that are turning red in the replate flasks. The mother flasks still look great (nice and green) so I don't think they are 'browning out' but may be suffering a deficiency? The color just started to appear once replated. It's not on the leaf margins, but is affecting the new growth, so I don't think it's a lighting issue. The area in contact with the new media is fine, but the tops of the p-corms and the youngest growth is affected. It's not contamination (I'm very familiar with what that looks like )


Any help is appreciated. Oh, and it's not a picky or iron-needy species, just a hardy old Encyclia.