You don't specify a budget for this. If it HAS to be white (A very impractical color for a cue base BTW) then one person I know who can make it is Jack Justis, who has built custom cases using white Italian leather
like these.
It won't be cheap thought (Pricing is
here, the white leather is a $150 option on top of the basic case price.) If you need something cheap I have no idea. I don't see why a cheap case can't be made out of white vinyl just like any other color, but there's probably been little or no demand for it.