Nikon Capture NX question.
When you say "rendering," if you mean what you wait for when you first open the file...I believe what you see first, while the "rendering" is being done, is the NEF file before the in-camera settings are applied. If you have boosted saturation, sharpening, tone (curves), etc., you'll see them applied by the "rendering." Depending on what the settings are, the image may appear more "cranked up" after the file is rendered.
Apologies if I've misunderstood your issue...