Multi colored fluorites help clear negativity from the atmosphere, helping to protect and stabilize you, clearing and repairing the auric field. Ones with more purple tend to work with the mind to access the spritiual dimensions, supporting brain chemistry and helping with dizziness. yellows magnify creativity and energy while the ones with more green tend to work on cleansing the heart chakra. the ones with more blue are good for the throat chakra and kproblems with speech or public speaking.  Their various colorations make them excellent healing sotnes for multiple purposes and in general, they just feel good to have and to hold onto in times of stress or anxiety.