Handle monochrome CGColors as well.
Handle monochrome CGColors as well.

It seems that snow leopard is storing some colors as grayscale. This
means that we need to handle them or otherwise things go very black.
It's an easy case to do as well, so just do it.

Reviewed-by: Bradley T. Hughes

RLovelett/qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,radekp/qt,KDE/qt,radekp/qt,pruiz/wkhtmltopdf-qt,pruiz/wkhtmltopdf-qt,KDE/qt,igor-sfdc/qt-wk,radekp/qt,KDE/qt,radekp/qt,igor-sfdc/qt-wk,RLovelett/qt,radekp/qt,pruiz/wkhtmltopdf-qt,RLovelett/qt,igor-sfdc/qt-wk,radekp/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,radekp/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,radekp/qt,radekp/qt,RLovelett/qt,RLovelett/qt,KDE/qt,pruiz/wkhtmltopdf-qt,KDE/qt,KDE/qt,KDE/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk,igor-sfdc/qt-wk,igor-sfdc/qt-wk,RLovelett/qt,RLovelett/qt,igor-sfdc/qt-wk,pruiz/wkhtmltopdf-qt,radekp/qt,KDE/qt,RLovelett/qt,pruiz/wkhtmltopdf-qt,igor-sfdc/qt-wk