Red is a tough color to render properly with digital photography. First, the sRGB color space doesn't have an extended red gamut, so it tends to clip the red channel for reds and yellows. Clipping the red channel will lead to "out of whack" colors and a significant loss of detail, sometimes with the red areas looking like just a solid mass of red instead of an area with detail. Add to that the fact that as a society we're constantly exposed to super saturated colors (more eye catching for advertising) and beginning to think that is how red should really look, so the camera manufacturers/raw software developers are bumping up the default saturation in rendered images. This further exacerbates the issue of clipping the red channel.
There's no really good answer with respect to how to better handle reds. Some of the other color spaces have a wider gamut in the red channel, and are therefore better suited for images with saturated reds; however, our computer operating systems, software and displays haven't quite caught up to where they need to be in order for us to be able to use a wider color space without problems. If everybody were to use color managed software, calibrate their wide gamut (very few are) monitors properly, tag their images with an appropriate color space (Adobe RGB or wider), and use color managed browsers, then we would be able to migrate to using a wider color space when posting web images. However, if even one of those criteria is missing, then an image with a wider color space can look REALLY bad when displayed. So, we tend to default to the least common denominator, which is to use an sRGB color space, which will look the best (in general) on most "consumer" monitors.
Given the limitation of using a color space that can't contain all the red data without clipping, we sometimes have to make the choice to lower the overall exposure in order to keep from clipping the red channel. Here's an example of an image where I made the conscious decision to lower the overall exposure of the image in post processing in order to prevent clipping in the red channel:
If I would have kept the "normal" exposure, I would have lost all the detail and tonal gradations in the rose. (I also lowered the red channel using white balance adjustments, which gave a little bit of false color to the rose (it's a bit too green on some of the petals), but that again was a conscious decision to keep the red channel from clipping.)
Hopefully this makes sense?
Keith
