An alternative way to demonstrate green glow is like this:
Attached to this post is an image of a night sky, with some stars on a
pure black background:
If you look at that image (open it in a separate tab and press F11 to make it full screen; Esc to exit that mode) on a normal LCD computer monitor, in a room with the lights turned off, you'll see that even when your monitor is trying to display pure black, it's still very bright compared to the rest of your room. This all happens because the little liquid crystals that are meant to go opaque to block out the light, simply can't achieve full 100% opacity.
With the F-35's current LCD-projector tech, that very bright "black" is also being projected / reflected off the pilot's visor. What should just be some green lines and text on a fully transparent background is instead some green lines and text on a paler but not fully transparent green background.
This all happens because LCDs work by blocking light coming from light bulbs in the rear of your monitor. In older LCD displays there are fluorescent tubes in the edges of the monitor and they shine light through a plastic filter that spreads it out evenly towards the middle of the screen. If you've ever bought an "LED" TV or monitor, they're also LCDs, but they just use a grid of LED lights to create the same effect. Then, to control the colour, brightness, etc of the image on your monitor, every pixel on your screen has 3 little liquid crystal 'sub-pixels'; one is red, one is green, one is blue. To display a pure black pixel, those liquid crystals try to fully go opaque, but liquid crystals cannot achieve 100% opacity, so light gets through.
With OLEDs, there are no liquid crystals and there is no backlight (no fluorescent bulbs in the rear or grids of LED back lights). Instead, every pixel consists of microscopic red, green and blue LEDs and they just light up as much as needed. To display a pure black pixel, those LEDs just simply turn off completely and emit zero light.
So with the new OLED project tech in the F-35's HMDS, the symbology will still be lit just as well as before, but now the areas between text and lines will be vastly more transparent, because the only light that'll be shining onto the visor in those areas will be background luminance (lights shining inside his cockpit and reflecting off his face), which will be a tiny fraction of what the pilot experienced previously.
You can also see a similar result with your phone if you have an OLED / AMOLED display (Samsung Galaxy phones from recent years, the iPhone 10 family - any phone that features an "always-on display" with a clock still showing when the screen is off). If you open that same night sky image you should notice that if the pure black of the background blends seemlessly into the bezels / borders of your phone's display, because it's just (under the glass) black plastic bordering against black plastic.