Why Is The Sky Blue?

Why is the sky white sometimes instead of blue and the clouds with it blue instead of white?

• We had several beautiful days and the sky was very blue and the clouds very white, beautiful and puffy like cool whip (yum). Today, though, the clouds blue, and I understand its going to rain eventually and they are filled with water perhaps but I don't understand why the sky is white instead of blue unless that indicates that the sky is fuller with a variation of clouds, both white and the ones with more water in them, the blue ones. I think I've answered my own question but I'd like to hear a confirmation of that from someone that knows. Tx

• Answer:

  Sometimes there are very thin clouds that cover the sky before the arrival of thicker, more developed clouds. There are clouds with large amounts of moisture, which will appear as blue from a distance, but gray while near them.