Wow, it was really hard to find information on this. Based on what I have learned from visiting roughly a dozen websites, I don't think you should get a tattoo. According to the American Osteopathic College of Dermatology, "Micropigmentation (tattooing) is rarely recommended. It works best for the lip area, particularly in people with dark skin; however, it is difficult to perfectly match the skin, and tends to look worse over time." Instead they recommend using self tanners. "Sunless tanning preparations may be used to darken the vitiligo a more acceptable color. These will cover small areas of vitiligo well." One other thing to consider is this: some people with vitiligo experience pigmentation loss after a cut or scratch to an area. So, I don't know that it's a good idea to purposefully have needles applied to the skin.
But that's just my opninion. It's something to think about, anyway. God luck with whatever you decide.