By default, Firefox will try to color manage JPEGs and PNGs tagged with a color space but not others. You can review and experiment with the following preferences to see whether one of them improves the rendering: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button promising to be careful. (2) In the search box above the list, type or paste '''gfx.c''' and pause while the list is filtered '''gfx.color_management.mode''' - governs application of color management to images * 0 = off * 1 = on for ALL images * 2 = on for TAGGED images (default) ''I can't recall whether you need to exit/restart Firefox before changes to this preference, or changes to the below preferences, takes effect.'' '''gfx.color_management.display_profile''' - if you have created a custom monitor profile and Firefox is not using it, you can enter the path to it here. '''gfx.color_management.enablev4''' - double-click to toggle to true if your custom monitor profile is an ICC v4 profile '''gfx.color_management.rendering_intent''' - whether Firefox honors or overrides the intent flag in the ICC profile, by default, overrides to Perceptual ''For details, see:'' https://developer.mozilla.org/Firefox/Releases/3.5/ICC_color_correction_in_Firefox Can you find a combination of settings that gives you the colors you expect? If you want to share a link to a particular image for comparison, please feel free.