What is the meaning of pink clouds in a dream?

Most objects in dreams don't have any meanings. Some dreams as a whole have a meaning, but not specific objects. This is because each brain uses the objects that have some kind of emotional association with them, and so for each person they are different objects. For example, if seeing pink clouds in books excited you while you were a kid, your brain remembers this connection: pink clouds => excitement. So now, if your emotional state is excited and happy, you may dream of pink clouds again. Or, if you're sad or depressed, this same symbol may be used by your brain to reflect that emotional state. For example, you could dream of standing in front of tinted glass and seeing pink clouds far-far away - this would represent that you're away from your excited/emotional state and long to return to it.

Because brain only renders our emotional state in the dreams (and only sometimes), the meanings are always related to present feelings and emotional state, and can never tell you future (if anyone tells you otherwise, they just want to make money off of you). Most dreams, however, are completely random, due to the nature of signal processing by our brain while we sleep, and have absolutely no meaning. Often, brain also reacts to physical sensations while you sleep without any warning - for example, if you like pink clouds and you like light breezes, you may see pink clouds in your sleep if your body feels a light breeze from, say, a ceiling fan while you sleep.