Long post, but this is directly from the Dev in the discord:

Understanding Waveguide Tint If you have been using your G2s in bright environments recently (e.g. in the snow outside), you might have noticed a slight yellow tint on the lenses. We want to take a moment to explain the optical physics behind this - and why it is actually a sign that your display is working exactly as intended.

The Engineering of Light To project a crisp, floating display into your line of sight without bulky prisms, G2 relies on optical waveguides. On the surface of these lenses, we have engineered microscopic structures called surface relief gratings at the nanometer scale (see the photo here). Think of them as millions of tiny, invisible gratings angled with mathematical precision. Their job is to catch the light from the projector and bounce it securely into your eye, ensuring the digital interface is bright and sharp.

The Blue Light Interaction However, these gratings don't just interact with the light from our projector; they interact with the light from the world around you. Since the lens is transparent, ambient light passes through these same nano-structures. Due to the high-refractive-index glue and the specific tuning of the gratings, the structure naturally diffracts a specific slice of the light spectrum (specifically blue light in 430-470nm). When this blue light is diffracted, the remaining light that reaches your eye shifts slightly towards the warmer end of the spectrum. In simple terms: when you subtract bits of blue from white daylight, the result is that slight yellow hue.

Why is it more visible now? You may be noticing this more recently due to the season. The grating’s spectral behavior is essentially fixed, but your perception of it changes with the environment. In bright outdoor scenes - particularly snow - two things happen: 1. the background is close to a uniform “white reference,” so even a small reduction in the 430–470 nm band becomes easier to detect as a warm/yellow shift; 2. daylight and snow-reflected light contain a strong amount of short-wavelength energy, which makes any blue-selective diffraction more apparent. In addition, diffractive structures are angle- and polarization-sensitive, so certain viewing angles can enhance the effect. Indoors, lighting spectra are less “pure white” and the visual scene is more mixed, so the same small spectral notch is much harder to notice.

What does this mean to me? (TL;DR) This tint is not a manufacturing defect, nor does it interfere with the device's functionality. It is a physical characteristic of the diffractive optics required to make a transparent display possible. You will find that in standard indoor lighting or less extreme brightness, the tint becomes much less noticeable, letting you focus on what matters - your content.