Is There a Black Hole?

Even for a black hole, it's fairly continuous. Things get gradually redder and redder before they fall in the event horizon. But wouldn't people have seen these? Maybe in the infrared? Like if we look out into the center of our galaxy,. Wouldn't then we see a huge source of infrared light? Yeah, but the infrared radiation would be crazy long wavelengths. We do not have sensors that can pick up infrared radiation at the frequencies.