S.Y.
Having to pump will often decrease your supply. Baby just nurses different and gets more, usually, I think. Depending on how much you're getting out wach time you pump, I would say that it could be white bc your milk comes out in different levels. First it's the fatty stuff (I think?) and then it's the part that is more filling and has all the nutrients. Maybe I got them backwards... I don' have a lot of success pumping (3 kids, 5 different pumps, and I still can't get more than 2 oz in 30 min) so I usually get the white milk and stuff...
Good luck!