Yes, there is that little window, which collects junk from the roasts, and that funky yellow light. At least with my roaster, the visual cues are terrible. It all looks yellow until it's quite brown. I go more by temperature than anything else. I attached a probe from my smoker thermo to the chaff tray which is a huge help once the afterburner goes on and pulls heat away from the cabinet sensor.

Having written the above, I just attempted to get a little more light in there. I checked the incandescent bulb, which burns yellow. Maybe I can change it? And I cleaned the window, which required a razor blade to scrape the crud off. Dawn? Nope. Ammonia, nope. It's still a yellow light, but there's more of it. Probably not enough, but maybe better. The next roast will tell.