If it is tan and opaque, there was plenty of sperm to fertilize eggs. This was a well mated queen. If it is milky and translucent, the supply of sperm was running low, either from age or inadequate mating. What to do with this information. The next time you see these signs you'll have a better idea of what condition the queen is in.
More information makes for better decisions.
If the queen was newly purchased, and the spermatheca was not opaque, therefore not fully mated, let your queen breeder know this information. This feedback is important so queen breeders can find ways to remedy the situation by providing more drones. Weather conditions, such as cloudiness or temperatures less than 69 degrees during mating periods can contribute to low sperm count. We can't change the weather but we can add more drones.