I am not an authority on this (by any means). But it seems to me like someone has posted this type of question before on this site.
Since I believe your question to be "Should they be black or white?", I think someone posted that sometimes the stripe matches the interior of the car. However, there are cases (like ours) when the interior is blue to match the car and the stripe is white.
As well, since there is nothing on the build sheet, it appears to me like you have the freedom to put black or white, depending on preference.
There are others like Paul N., and Bob Teets who know much more about this than I do. Hopefully they will respond.
Paul