If the color of hydrate were identical to the color of the anhydride, how could you be sure that you had driven off all the water from the hydrate?

Answer is: you can calculate the number of moles of water in a hydrate if you know the empirical formula of the anhydride.
First measure mass of hydrate, after you heat hydrate, put sample of the compound on scale and measure the mass loss. The lost mass is water. Now  calculate the number of moles of water and if the ratio is same as empirical formula, all water is lost.

In meteorology, a  cloud  is an aerosol consisting of a visible mass of minute liquid droplets, frozen crystals, or other particles suspended in the atmosphere of a planetary body. nephology is the science of  clouds, which is undertaken in the  cloud  physics branch of meteorology.cirrus clouds  usually describe clouds high in the atmosphere that can include wispy clouds, typically with ice crystals. variations include cirrus, cirrocumulus and cirrostratus as defined by the cloud's position in the atmosphere.layered stratus clouds  have both flat tops and bases, and can appear as if they take up the whole sky, stretching from horizon to horizon. other combinations and variations include stratus, stratocumulus, nimbostratus and altostratus.cumulus clouds  often pile up in multiple layers of the atmosphere, representing clouds that develop vertically. cumulus clouds often look like pillars with anvil-type tops or columns of clouds stacked vertically. variations include cumulus, cumulus-congestus, cumulonimbus and altocumulus.

Yapo 13 fool coming at you for it