Just the usual learning curve! We prefer newbies who ask rather too much by far to those who ask too little and only when they are in deep kimchee! After all, you can only judge what is wrong when you know what is normal!
At that opportunity, may I tell you that you should not panic if you come across some milky white pee sooner or later - that is just a sign that excess calcium has been secreted the normal way. It dries to a powdery white patch and can make poo look "mouldy" when a piggy happens to spray its pee over some!
Guinea pig pee often discolours to rusty and orangey tones when in contact with the air. Sometimes food can also discolour urine. Only when you notice bright pink pee do you need to be worried - that is an indication of blood in the urine and means that you need to have your piggy seen by a vet. More often than not, it is the onset of a urinary tract infection to which piggies are quite prone.