An unusual tri-tone feature is found in this Cal helmet. As we know, this helmet was originally yellow out of the factory mold. This particular batch of yellow glass contained green cullet that was diluted into fine swirling throughout. As you can see, the upper half of the insulator was exposed to more UV rays of the sun and turned purple. The lower half was partially protected (possibly painted), resulting in the preservation of approximately 50% of the original yellow hue that distinctly bleeds through some of the purple.

The fine green swirls throughout this insulator present an interesting color mix, especially in the lower half, where it exudes an overall smokey, swampy tone from the yellow/purple/green mix. The upper half, especially the ears, exhibits some nice green swirls in the purple glass.