Golden Retrievers are known for their golden coat, which can range from light cream to a rich, dark gold.
The American Kennel Club (AKC) breed standard actually disqualifies dogs with "any solid color other than gold." So, while there may be some variation in shade, true Golden Retrievers should have a golden coat.
If you see a dog that looks like a Golden Retriever but has a brown coat, it's likely a mix breed.