I recently posted this for somone else... I have both fir... AND yellow pine floors in our upstairs. The pine is original, and I used fir in the addition because I could not get matching pine. They are very close in look, when the fir is cut "vertical grain".
Here is where the two floors meet. Fir on left, pine on right.
In this photo you can kinda see what the original yellow pine floor looks like:
![Image](http://i154.photobucket.com/albums/s259/saracenihouse/new%20photos%20024_zpsd4odrdhd.jpg)
This is the new fir floor, just after being installed back in 2005 (the rest of the room was still under construction):
![Image](http://i154.photobucket.com/albums/s259/saracenihouse/master%20bedroom%20floor_zpse4ldufcz.jpg)
So as you can see - it's very close! All things being equal, though, I would say you have yellow pine.
Chris