Colors of the images in the frontend are suddenly displayed darker after an upgrade

After upgrading a TYPO3 site, more precisely after upgrading ImageMagick, it can happen that colors of images are suddenly displayed darker. This is because, from version 6.7.5-5, ImageMagick no longer uses the RGB color space, but the sRGB color space. However, you can adapt your TYPO3 site to this change in just a few steps:

In the install tool or in the LocalConfiguration.php/settings.php under GFX the following entry:

'processor_colorspace' => 'RGB',

change to:

'processor_colorspace' => 'sRGB',

Then in the install tool under "Maintanance > Remove Temporary Assets" empty the relevant "_processed_" folder from which the dark images previously came. Finally, empty the frontend caches, then the images should be displayed in the correct colors again.