To elaborate, that's supposed to happen "in July," but the change hasn't shown up yet on Tesla's Web site. Currently, black is the default color and pearl multi-coat white is a $1500 extra. Once the change happens, white (presumably not the pearl multi-coat variety, but something simpler/cheaper) will be the default color and black (maybe the same black that's available now, maybe not; Tesla has not officially elaborated, AFAIK) will become a $1,000 option. If you want either black or white, and depending on how fussy you are about the specific type of black or white you want and how much you're willing to pay for it, you might want to buy now or wait; but waiting for the color/price change means taking a gamble, since the exact details of what will be offered remains unknown. AFAIK, no other colors will be affected by this change, but color changes are the sorts of things that Tesla sometimes springs on the public with little advance notice. Also, even post-change, there may be some inventory cars with the old black and white colors available. (OTOH, Tesla's just finished its end-of-quarter delivery push, so inventory is likely pretty low now, and it's conceivable they won't be building any more with the old colors.)
As you might gather from the above, Tesla often leaves its customers guessing. So do other automakers, of course, but others tend to make changes only when model years change, or they may make occasional mid-year changes involving "limited production" colors.
