Very brightly-coloured clothing present a unique problem in post-processing. Most commonly it’s red and orange garments, but it can happen with any vivid colour. They’re invariably out of gamut, and cause channel clipping. If you shoot Jpeg and this happens, you’re screwed. Make sure you shoot Raw, so that you have plenty of latitude for dealing with it.
When time permits, I intend to write more comprehensive information about this. For now, here’s a brief overview of your four options.
Ignore the clipping. This is a genuine option – a lot of people don’t mind a bit of clipping in clothing. Remember that this whole issue boils down to a choice of "bright and clipped" vs "dull and safe". You might prefer the former over the latter. (Of course, some clipping is so severe that it can’t be ignored.)
Process the raw file with correct exposure etc, then use the adjustment brush to desaturate the area (if your software has an adjustment brush). In some cases reduction of exposure is better than desaturation; in other cases it needs a little of both. I don't recommend this option.
Process the raw file a bit underexposed and/or undersaturated. Then, in PS, selectively increase the exposure and/or saturation of areas that need it. Obviously the clothing wouldn’t be one of those areas.
Process as normal, in a large colour space. Then take it into Photoshop (still in the large space), and desaturate the clothing until it’s within the sRGB gamut and can be converted safely.
The last option is only for VERY extreme cases. I do not recommend it.
If you have a question about this article, please feel free to post it in Ask Damien.