I have been experimenting with different cookies and icings. I made adorable candy corn shaped cookies and I bagged them about 2 1/2 hours after I decorated them. I really thought that they were dry, but when I got up to bring them to work this morning all of the cookies had some of the orange color running into the yellow. Four of them were perfect. I used a recipe that I found on Karen's cookies and we really liked the flavor. Will my cookies get stale and hard if I leave them out and uncovered overnight?

Lisa, I think some people leave theirs out, but actually I put mine into rubbermaid airtight containers to dry. My RI sometimes drys 'glilttery' and my TG isn't as glossy as others, this may be the reason. But, I don't want to give someone a dried-out cookie. Now, I do have to have several of those 6 to 7 dollar containers from walmart (I think they're rubbermaid), because I don't want to stack the cookies until they are dry. After they are dry, then I will stack them with parchment between layers in airtight containers.
Hope this makes sense.
But, yes, if you put two colors together while they are still wet or not completely dry, you get that bleeding thing going on. Hate that!

The big containers are a good idea and probably worth the investment. I LOVE to bake and decorate to share with the people at work, but I like them to look nice when I do. Thanks

You didn't mention what type of icing you used -- 2 1/2 hours isn't long enough for RI or glace.

I leave my cookies out overnight to dry and have never had any problems. I place the cookies onto cookie sheets with rims and lay a piece of waxed paper over the top. The sir circulates and they dry just fine. Once they are completely dry I store them in airtight containers.