To clarify: Do you mean the Cedar boxes were painted with a Redwood stain?

Asking cause our fence put up two years ago was a choice of cedar or redwood...looked like redwood and that is what the paperwork said....we sealed ours with Kilz and then painted to match the rest of the fence around the house. We had gone half with the neighbor and they were made that the wood was warping...saying we watered too much. Of course they did not paint their side.

Now we are replacing the back fence and the man giving estimates said the fence was not cedar or redwood, but a softwood painted to look like redwood.

No the cedar is raw at the moment. And it is real cedar. I live in an area where we grow it here. It is tongue and groove, smooth 1 side, rough the other. There is nothing on it yet. Your posting brings up an interesting point. I will more than likely have to paint both sides, as warping will probably occur with only one side painted.

I would suggest that instead of painting you should get a penetrating oil stain. They can be mixed in many colors including black. Good quality stain will not peel and will also protect the wood from UV damage

Any Home Depot/Lowes will have fence and deck stain that will work fine for this. You may even find an "oops" can for a few dollars and have them add in some more black pigment if it is not a color you like.

A number of years ago we built some cedar planter boxes and I used Olympic opaque oil stain inside and out. The stain never blistered or peeled and outlasted the wood, which finally rotted out. They don't make stain as well now, but it still holds up better than any paint.