Comment # 17 on bug 954146 from Marcos Mello

I think on GNOME3 it happens too. I modified these options in
/etc/sysconfig/fonts-config:

FORCE_HINTSTYLE="hintslight"
USE_LCDFILTER="lcddefault"
USE_RGBA="rgb"

And then run fonts-config as root.

Attached images of Firefox and Epiphany rendered text.

I do not remember changing GNOME configuration. But here it is anyway:

$ gsettings list-recursively org.gnome.settings-daemon.plugins.xsettings
org.gnome.settings-daemon.plugins.xsettings disabled-gtk-modules
['pk-gtk-module']
org.gnome.settings-daemon.plugins.xsettings priority 0
org.gnome.settings-daemon.plugins.xsettings hinting 'medium'
org.gnome.settings-daemon.plugins.xsettings overrides @a{sv} {}
org.gnome.settings-daemon.plugins.xsettings rgba-order 'rgb'
org.gnome.settings-daemon.plugins.xsettings antialiasing 'grayscale'
org.gnome.settings-daemon.plugins.xsettings active true
org.gnome.settings-daemon.plugins.xsettings enabled-gtk-modules @as []

Running openSUSE 42.1 here.