For some silly reason I assumed that the Gimp color picker's displayed colors are accurately displayed if one is working on an sRGB image. But that isn't true because the Gimp color picker isn't color-managed. Instead the color picker RGB values are sent straight to the screen without having first been converted from the image's working color space to the monitor profile.

What this means in practice is the only time the color picker's color patches are displayed accurately is if the monitor has been calibrated to match the working color space that the image itself is actually in.

The only working color space to which most monitors traditionally have been calibrated is sRGB (ColorMatchRGB and AppleRGB being two notable exceptions).

So unless your monitor has been calibrated to sRGB *and* your image likewise is an sRGB image, the Gimp color picker won't show you accurate colors. The color picker RGB *numbers* are accurate but the displayed *color* is not. The farther your monitor's actual calibration+profile is from sRGB, the farther off the displayed colors will be from what they ought to look like.

The only practical solution to the problem of un-color-managed and hence inaccurately displayed color picker colors is that you calibrate your monitor to match sRGB and then only work on sRGB images.

One problem with this practical solution is that you *can't* calibrate most LCD monitors to 100% match sRGB. If you try, you inevitably reduce the color gamut of your LCD monitor, there's a good chance that you'll introduce banding, and you still won't get a completely accurate display of the colors that you've color-picked. See: sRGB, the Universal Monitor Profile Not So Good for LCD Monitors (http://ninedegreesbelow.com/photography/srgb-bad-monitor-profile.html)

Another problem with this practical solution is that most of today's LCD monitors, even wide-gamut LCD monitors, *can't* display all sRGB colors. Wide-gamut monitors have color gamuts that are larger than the sRGB color gamut, but almost none of them entirely encompass sRGB. According to a monitor profile for a recent $2500 wide-gamut monitor, even this very pricey monitor can't display *all* sRGB colors, being weak in blues compared to sRGB. The monitor profile for a recent $450 consumer-grade monitor indicates that it could only display 88% of all sRGB colors. See: sRGB: good working space for CRTs, not so good for LCDs (http://ninedegreesbelow.com/photography/srgb-bad-working-space-profile.html)

If you use sRGB as your monitor profile for your uncalibrated monitor (or if you disable color management) and you work on an sRGB image, the color picker's displayed colors *will* match the colors that you color-pick from your image. But it's a virtual certainty that the colors you see are very far from accurate.

Best regards, Elle