Help! - Oak/Hickory Seedlings Losing Color

[Uncreative]

I'm new to this and here's my problem.

Two weeks ago I transplanted my oak and hickory seedlings to an air pruning set-up for the summer. I kept them in the garage for a week to begin acclimating them to being outdoors. I am using the smaller-leafed ones for bonsai, so I trimmed their roots and have not moved them out yet, but plan to this weekend.

The seedlings for bonsai, having gone through getting their tap roots cut, are doing pretty well. But the non-bonsai seedlings outside are losing their color, as seen in the attached pic. We tested the pH and it is between 6&7. I suppose they could have gotten burned in the sun? We've only had a few really nice days this past week and they are in a sunny place. Now someone is telling me they should only have 3 hours/day.

Higher resolution images are available at:
http://img31.imageshack.us/img31/2927/img2850.jpg
http://img31.imageshack.us/img31/2835/img2849.jpg

What's happening?

[bullthistle]

They may be right, but they were growing outside first weren't they so place them were you dug them up. Anything transplanted goes into shock but if you are worried only give them 3 hours. FYI you should also prune the roots back and not just for bonsai.

[Uncreative]

I actually grew these from acorns over the winter, but I was worried about them being stressed from the transplant. Could this just be a stress response, and if so, do you think they'll rebound? The new growth on some seems to look good.

What did you mean about trimming the tap roots even if not bonsai? The roots do not reach to the bottom of the container yet and should be air pruned when they do. Any other concern about trimming? I know it's probably too late now, but hope to get this right before trying again next year.

Thanks for any more input.