it stands for being a star and honesty
--- nautical starts symbolize loyalty and finding your way through hard times. It is said that sailors back when would get the nautical star tattoos to symbolize the north star; which they used to find their way on the oceans.
purple can symbolize royalty (as seen in older monarchies and in the church to represent jesus/god) and it can represent spirituality. purple is considered to be sacred because it doesn't show up in nature as often as other colours like red for example.
I have two nautical star tattoo's. One is purple and I got it to represent my grandfather who passed away a few years back because he is one who helped me stay grounded and find my way through anything that life threw at me. And I got it in purple because a)it is his birthstone and b) because of the spirituality aspect of the meaning of the colour purple.
All in all, a tattoo can symbolize anything you want it to.