I have found that whilst they are young and produce poop/urate every day, the urate tends to be white, indicating that they are well hydrated. As they get older, they poop less often - take my old boy Tommy, for example, he would only produce once every 7-10 days or more, and even though he would drink every day his urate could be quite yellow/orange at times. The longer the urate stays in the body, the more water gets absorbed from it, hence the more orange appearance. The last part to leave his body (the end that had been in him the least amount of time) was always white. Also, sometimes they will only produce a urate, or the poop can get separated from it depending on how far it falls in the cage and where it lands.