I ordered HUMBLE Band Strap for Xiaomi Mi Band 3/ Mi Band 4 from Amazon with Navy Blue color.
I ordered this band looking at the pictures in which it looks like a Navy Blue band but on delivery, the color of the band was not navy blue. It was more like a typical dark blue with a purple tinge. In artificial light of the night it totally looked like a purple-colored band.
Overall the quality of the band is good and just like the original Mi band.