Does Aperture do this?
The tech note on the Adobe site says that one module of Aperture displays phots in AdobeRGB and another uses the Prophoto color space. Why not just one color space in all modes?http://kb.adobe.com/selfservice/viewConten...33659&sliceId=2
If you read the last paragraph of the quoted article, you will see that the differences are most likely not related to the color space, but rather to the fact that the library views are from a cache and may be subject to artifacts, which are usually removed if you view at 100%.
If you view the same file in Photoshop in ProPhotoRGB and then after converting to sRGB, they usually appear exactly the same because of the effectiveness of color management. The ProPhoto file may have a larger gamut of colors, but these can't be displayed on most screens which have a gamut similar to sRGB. Some high end monitors can display the aRGB gamut and a difference could be seen with such a monitor if the ProPhoto file contained colors outside of the sRGB gamut.
Since the conversion process with matrix files is relative colorimetric, in gamut colors are not affected and out of gamut colors are merely clipped.
I think that the native color space of Lightroom is ProPhotoRGB primaries and a gamma of one, so it does in essence use a single color space. I find no mention of Aperture in the Adobe article and have no experience with Aperture.