Welcome to Android Central! Do you notice the same kind of quality with YouTube or other video apps?
One thing you can do to perhaps tweak your display a little bit is to change the display mode. What kind of phone do you have? Try Settings --> Display--> and look for something like "Screen Mode." Maybe you'd prefer a Saturated or Vivid selection, depending on what your specific phone offers.
Is the video within Netflix too zoomed out? You can zoom in on your Netflix video by pinching to zoom in.