What can be said about the polarity of water

Water's polarity can be responsible for many of it's properties including it's attractiveness to other molecules.  Water molecules attract one another based on the attraction between the positive end of one water molecule and the negative end of the other. Also the unequal sharing of electrons gives the molecules a slight negative charge near it's oxygen atom and a slight positive charge in it's hydrogen molecule.

The answer is joseph is observing the colour of the reaction mixture to see whether proteins are present in the given solution.