the color of light emitted depends on the energy emitted by each electron returning to its original state. for example, the red region of the flame contains a high proportion of particles with a difference in quantum state energies that corresponds to the red range of the visible light spectrum.
because of the prism that reflected from the light
there are different kinds of soap for their uses. Soap like bleaches , are used in a laundry . Soap like bath soap is used for bathing . Different kinds of soap is important for us to know what is the uses for that particular soap.