CSS Simon wrote:
ProPhoto is Lightroom's working space, and it can't be changed.
Pretty close. The processing is done again with ProPhoto primaries but with a linear 1.0 TRC so we can't call it ProPhoto RGB any more than we can call MelissaRGB ProPhoto RGB. The only place we 'get' ProPhoto in LR is if we export specifically to that color space and in LR 4 we can now soft proof and thus update the numbers to ProPhoto RGB.