Dreaming of nappies in general indicates that you are anxious or worried about persons in your immediate vicinity.
You are not taking time for yourself, and when your focus should be on your own life, you are either paying too much attention or devoting too much time to others close to you. In general, they are positive wish dreams that speak of things coming true if you pay attention to the correct parts of your life.
Nappies bring good fortune, but they also come with a warning. If you notice other people (adults) wearing diapers in a dream, then it's a sign that you should review your finances and make sure that you're not wasting money that may be saved. Wearing a nappy, on the other hand, signifies that you have a strong financial future ahead of you - that you will be well taken care of. Another typical interpretation of a nappies-related dream is that you need to take the time to consider the two sides of a situation in your life.
Sometimes nappy dreams are about wanting to have a baby or being fertile. When your dream is about the baby's nappy rather than the baby itself, whether it's about the colour or type of nappy (or even whether it's dirty or clean), it could mean that you're not ready to have and raise a baby yet and need to get other things in order first.
If you (or someone close to you) are pregnant and your dream involves changing a nappy, it is stated that if there was pee, the baby is a girl, and if there were faeces, the baby is a boy.