Can I just say that the stix aren't that important. I have just finished my 100 days Foundation course. I think only twice did the stix show that I was in ketosis (ie a pink stick). To begin with, I was terrified that my Counsellor would think I had been cheating (which I hadn't!) When I spoke to her about it, she told me not to worry about it - I was clearly one of those people that either it didn't register, or that I was drinking so much water, the ketones were barely traceable. Whatever the answer, I still managed to lose 9lbs in one week and a total of 4 stone 5lbs in Foundation - so clearly fatburning!!
If your stix are working, you should be aiming for the paler pink. The darker the pink/purple, the more you need to drink!