I used the atrium grate mentioned above in this bucket.
I have three buckets done. I used three different lids. I don't know if the color will make a difference or not. I'll just have to wait and see how well each one works.
I don't have a picture of it, but I did drill holes in the exterior buckets just below the bottom of the interior bucket. That way water can drain out if they get overfilled.
Now it just needs to get warm enough to plant stuff.