RebDoniel, the Rambam holds that the Tzitzis has to be the same color as the clothing. The Beis Yosef brings this. I don’t know about all white, but white.
By the way, RT, I don’t think you can apply Lo Sisgodedu to something that is not a Halachic type of Hanhaga, or Das Yehudis. Since there is no Kepeida on these stripes, it shouldn’t be Lo Sisgodedu if you don’t have it. We all have it but it’s not a Minhag.