Manual:$wgUseTinyRGBForJPGThumbnails

From Linux Web Expert

<translate> ImageMagick</translate>: $wgUseTinyRGBForJPGThumbnails
Swaps JPGs that use sRGB ICC profile with TinyRGB profile
<translate> Introduced in version:</translate>1.26.0 (Gerrit change 218372; git #584a2393)
<translate> Removed in version:</translate><translate> still in use</translate>
<translate> Allowed values:</translate>(boolean)
<translate> Default value:</translate>false

Details

When this variable is true and JPGs use the sRGB ICC profile, swaps it for the more lightweight (and free) TinyRGB profile when generating thumbnails.