No, there is no concept of the "speed of dark" in physics. Darkness is the absence or reduction of light, and it does not have a speed of its own.
The term "speed of dark" is sometimes used metaphorically or poetically, but it does not have a scientific basis. In physics, speed is a measure of how fast an object or phenomenon moves or propagates through space. Light, on the other hand, does have a well-defined speed, known as the speed of light, which is approximately 299,792 kilometers per second (or about 186,282 miles per second) in a vacuum.
When light is blocked or absorbed by an object, the region behind the object may appear dark. This darkness is not something that moves or has a speed itself; it is simply the absence or reduction of light. The speed of light determines how quickly the absence of light propagates in a given medium.
So, while we can discuss the speed of light, there is no scientific concept or measurement for the speed of darkness.