Based on the Swatch I decided to go with the gray/purple option. That my change when we see the first clue though.

After knitting a few double rows of the brioche section I decided to change the placing of the colors and use my main color as the foreground color, to make this color more dominant in my shawl.

I made the last garter ridge of the border with my main color in order to frame the large border better, it worked quite well.