If you read the link Kurt provided above, the answer is there.
For 69 the two place color code represented the bottom color in the first position, and the top color in the second position. The codes do not indicate stripe color, stripe color was based on the body, top, and interior color, There is an chart on this site that identifies the stripe color based on that info. Any non-standard paint was indicated by the - - code. That could be a special pain color, non standard stripe color, or stripe delete. If there is a special paint, and a rag or vinyl top on a special paint cat, the first - indicates special paint, but the top color is still designated by the second code. An example would be your Carolina blue with a black vinyl top coded - B, instead of - -. so custom paint color with a black vinyl, or convertible top.