Help enabling sub-pixel order on Mac. Seeing sub-pixel order Unknown.

[Nick]

I'm using xorg from macports on an iMac 27" and am trying to enable
sub-pixel ordering.  I modify ~/.fonts.conf and there is no update to the
variable.  Does anyone have suggestions on how to enable it?

$ xdpyinfo -ext RENDER | grep sub-pixel
    Screen 0 (sub-pixel order Unknown)

$ fc-cache

$ vi .fonts.conf
<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
<dir>~/.fonts/</dir>
<match target="font">
    <edit name="antialias" mode="assign">
        <bool>false</bool>
    </edit>
</match>
<match target="font">
    <edit name="rgba" mode="assign">
        <const>rgb</const>
    </edit>
</match>
</fontconfig>

Tried this section as well with no effect:
<match target="font">
    <edit name="antialias" mode="assign">
        <bool>false</bool>
    </edit>
    <edit name="rgba" mode="assign">
        <const>rgb</const>
    </edit>
</match>

$ xdpyinfo -ext RENDER | grep sub-pixel
    Screen 0 (sub-pixel order Unknown)