Does really distort ordinary PNG colors? Why?

Please help me understand how OS X Mavericks renders colors (or else how the Digital Color Meter app reports them).

Following Bjango’s advice on Photoshop color configuration for OS X, I found my way to this this tutorial on OS X color management, which included this PNG image which offers a grid of supposedly pure colors (I’m hoping stack exchange doesn’t modify the image, which is available at the tutorial page):
grid of colors

The tutorial page says you can check the rendering configurations of an app by viewing the PNG and trying to “Set your color meter to ‘Use native values’ and move the mouse cursor over each color swatch”.

When I open this PNG in the built-in, and sample the colors with Digital Color Meter with “Use native values”, I don’t get the correct hex values! For instance, the blue box in the top row shows up as 0x3F, 0x00, 0xFF. I also see wrong values in Safari!

Are Preview and Safari simply broken out of the box? I find that very hard to believe. Can anyone explain what on earth is going on? (I’m not looking for advice to use another app instead. I want to understand why I’m seeing what I’m seeing.)


Okay, never mind. I’m being dumb. “Display native values” displays the raw color values that are the result of the app and the system applying automatic color conversion from the inferred profile of the original image (sRGB for this file, I believe) all the way to the profile used by the monitor.

So “display native values” is displaying fairly useless information, since it depends on what monitor you’re using, and has no guarantee of producing the same color elsewhere (unless you’ve configured your system and yours apps to deliberately not do this conversion).

Source : Link , Question Author : algal , Answer Author : algal

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