Color Picker returns wrong color?

hello --

after spending the day trying to understand why the colors between a keynote file and my photoshop comp don't match i realize that it's probablt the apple native color picker which returns the wrong value, or a value based on a different color profile. as a little test. create in keynote a colored box with the srgb value: 64/5/26. after doing that, use the color picker sampler (little eye glass on top left) and sample the color of that same box. in my case it returns: 63/6/24 in the color profile (device rgb). i am not quite sure what is going on there. i am sure there is some logic to it, but it escapes me.

i speculate that the color picker uses a different color profile (device rgb) and converts the srgb in a slightly different way the adobe CMM does.

if anyone has some ideas, i'd love to get some suggestions how to fix this.

thanks in advance,

p.