I moved some seedlings that were in a sunny windowsill outdoors. They were in the sun for about 2 hours the first day, 6 hours the second day and maybe 8 today.

This evening I noticed that some of the leaves had areas that were a silvery-grey color. Any ideas what would cause this? Was it too much sun too soon? They may have had some over spray when I fertilized yesterday but other than that I see no signs of insects or anything else. I really don't want to lose these crosses so any help would be appreciated!

I would say too much sun too soon. Usually any kind of seedling needs about a week of hardening. Put them where they have indirect light for about a week, then start to introduce them to direct sun.

I agree with Gerry, the sun may cause some to even lose there foliage but they should survive, seems like every year I get in a hurry and the same thing happens to some of mine.

Thanks both of you. Back into indirect light they go!