Images in Library View, Full Screen View desaturated compared to Develop View

Just an additional comment to the quote above: The color space used in Develop vs. Library is a red herring. It's a very widespread myth that this in itself can produce different results on screen. In reality, anything that is correctly color managed will display correctly - i.e. identically. Whatever the source color space.

Library uses Adobe RGB previews. In theory, if you had a display with a gamut significantly exceeding Adobe RGB, you might be able to spot gamut clipping in those very saturated colors. But no such displays exist, so the question is moot.

In short - Jao is spot on. This is the monitor profile. Or possibly the video driver, which is just a different side to the same coin. In either case, something is causing the display color management chain to break. Both v4 profiles and/or LUT profiles are known to do that under some circumstances. V2 and matrix are always safer.

Or it could be extreme noise, which can produce vastly different results when resampled for screen below a 1:1 ratio.

How are you calibrating your display? What you describe is typical for a bad calibration display profile. You should set up your calibration software to generate icc v2 matrix profiles. It is also possible if your image is very noisy (think a shot of the milky way at 15 seconds exposure at ISO 3200) that you see differences in perceived saturation between Develop and Library due to the different way they scale the image. In that case, the images should look identical at 1:1 zoom.

Lastly, if the above doesn't do anything, you calibrate using a hardware puck and have icc v2 profiles or are using the built-in Color LCD profile try disabling the GPU acceleration (in the preferences pane->Performance).

I'm reposting an observation here from another forum user which I believe might help you understand your issue, I hope.

Also, are you calibrated?

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"This is pretty normal. One thing to realize is that as mentioned above the color space in Develop is different - it is a linear gamma version of prophotoRGB that is unique to Lightroom but that is not a real issue as long as the color is inside the display gamut and either adobeRGb or prophotoRGB. Most important is that the print module renders from the adobeRGB low res preview jpegs. The second (and probably most important in this case) is that the scaling algorithm is different. The jpeg preview in print is scaled I believe by bicubic scaling from the jpeg data but most importantly, the averaging of the pixels happens in gamma corrected space.

In Develop, the raw file is subsampled to lower resolution and then scaled in the linear space to the again lower display resolution. This results in a mathematically different result in high detail areas such as the colored leaves. This can lead to the Develop preview looking crisper and more saturated in the areas with lots of color detail as well as crisper in sharpness than the preview in Library or Print. There is no correct way to scale an image and the scaling algorithm has enormous influence so something to be aware off that it can influence appearance of scaled down images pretty strongly. To avoid this issue, the only solution is to zoom to 1:1 to check critical color."

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