Often artists will ask what oils I use.  And the answer is different manufacturers.  The manufacturer that has the hue I like and puts little else besides pigment and oil in the paint, usually is the one selected.  For example yellow ochre varies considerably among oil paint makers.  The same is true of Naples Yellow.  A good way to consistently get the hue you desire is to know the pigment code.   Here is a good reference.  http://www.artiscreation.com/ColorCharts.html