color/IR orthophotos as terrain source?

There seem to be a few sources around the web for free high resolution (often available in 1m/pix, 2, 5, 10, etc) digital orthophotos. Some are monochrome, and IMHO those are of dubious use - the artificial coloring techniques look unappealing to my eyes. But some are also in color/IR format - seems like maybe 4 channels (R, G, B, IR) collapsed to three (RGB).Of course everything comes out looking all red due to the IR channel, so they aren't usable directly. But has anyone ever experimented with doing some color corrections on them to bring them back as close as possible to natural color?To a first order approximation, I figure that everything that's red should end up green, since the heat is mostly given off by vegetation. To a second order approximation I guess this won't be quite true, because there are some brownish areas (dirt, rock) that should remain brownish. But maybe with suitable massaging, a convincing correction function could be found.Seem plausable to anybody else? If I can find some time, I might dig into this a little bit and see what I can come up with.