Strange colors

[BeyondTheGarden]

6 weeks ago I got a dozen Chamaedorea radicalis seedlings from Jeff at Floribunda.  Within the first week of potting, a lot of them faded to this yellow-gray hue (on the right of the picture).  I thought, maybe they just didn't take the stress of being bare-rooted and shipped to a new environment, and were going to fade to a slow death.  But in 6 weeks they haven't appeared to decline, and seem like they are fine despite their color?  

The picture doesn't quite reflect how dramatic the color difference is between the left and right examples. 

[Fusca]

I've noticed a change in different light exposure.  My cat palms in sun are a lighter green while those in mostly shade are a darker green.  Same with C. radicalis.

[BeyondTheGarden]

They were all growing together in the greenhouse, same light exposure, when the color difference first appeared.  Over the last week I have moved most of them indoors.  Some I have in filtered light, and I'm also trying a couple directly under my bright grow lights.  I read that this species can take more direct light, we'll see.