When I make a colour measurement using ColorPic (eg RGB levels, or CMK ), I get a somewhat different measurement to that of my photo editing software. If I paint a colour with the photo software and the measure it with ColorPic there are different values . Using the ColorPic parameters and painting with these there is a slight, but visible colour difference. It is not sampling area as these are uniform colours.

Which is correct? What does ColorPic measure?

CMYK Values do differ between applications. Some advanced photo editors have color management preferences that can be set to adjust CMYK. We've taken the more straightforward approach listed on wikipedia.

http://en.wikipedia.org/wiki/Cmyk

Thanks for your reply. It was a case of the colour management settings. I can now get the two measurements to
agree should I wish.

Regards