Is the black stripe wire positive or negative

Is the Black stripe line along the entire outside housing of speaker wire meant for the Negative connection? What about if the speaker wire has a White stripe, is that for the Positive?

Typically the black stripe on speaker wire is for the Negative signal (black connection on speakers / Black receiver binding posts). The positive speaker wire is usually a solid color (or clear with no stripe).

If there is a White stripe on speaker wire often times, this is wired to the Positive (Red connection / Red terminals)

That being said, it really doesn't matter though, as long as the negative terminal of the receiver matches the negative terminal of the speaker (usually black, but never red). People usual wire speaker wire so that the marked black side is designated negative and the other wire is positive.