You might want to search on color and colour in the Pages forum:
You can also tell Apple about things they should fix here:
I am looking after showing photos in a contest. I thought that Keynote would be ideal because I could read the comments on my screen and the judges would not see them. I have tested the slide show with 10 slides. In one of the slides, the effect is completely lost due to loss of saturation and loss of some magenta. I checked the Photo in Photoshop and it was bang on. I then checked it in Preview, again it was bang on. I then checked it in Lightroom and again the color was bang on. Hence Apple has put in the wrong color engine (or something) that is not managing the colors correctly in Keynote. Very disappointing. Nowhere can I find a place to set the color engine.
Am I missing something or is it an error an error on Apple's part.
Coming to this quite late (2 years), I can tell you I see exactly what you report with Keynote on 10.8 (as recently as 10.8.3 the other day, still broken). Photoshop, LR, Preview, ColorSync utility all show the embedded data correctly, Keynote doesn't. I'm running a dual display system where the 2nd unit is a wide gamut display and it 'feels' like Keynote is not honouring the correct display profile or not handling the data as tagged (which it is). Funny is the thumbnails in Keynote do show up correctly! Open a tagged Adobe RGB (1998) doc in all above applications and at least on my end, everything is correct Keynote.