We’ve identified an issue where bitmap images that are exported and re-imported into Sketch are appearing incorrectly and appearing washed out.
This is because macOS High Sierra renders certain gamma values in bitmaps differently to previous macOS versions.
If you’re using Sketch 47, we’ve fixed this bug already and all images exported from Sketch will have the correct gamma values and should render correctly. If you’re using Sketch 46 or earlier this bug will be fixed when you update.
However, if you’re creating and exporting bitmap images in other software and importing them into Sketch, you may still see issues with washed out colors.
To fix this, we’ve created a plugin that you can run on any Sketch documents that aren’t rendering properly. Simply click the link below to download the plugin, install it and run it once on each affected document. Please note, this plugin is only compatible with Sketch 47 or later.
Download the GammaCorrection plugin here.
To install just unzip the file, double click on the plugin titled GammaCorrection.sketchplugin and Sketch should do the rest.
Please note, this unexpected gamma rendering also affects other apps across macOS High Sierra and many existing images, outside of Sketch.
