Remove all Colorspace (HSV) and convert to black

[AnonConvert1]

I am looking to convert an image that has any color (Not black or white) and change to a specific color. For my test, I want to try black. But the idea is to remove all the color out of the image to my own desired specification.

I have looked through the options and can't seem to find what I am looking for. Would greatly appreciate the help!

[xnview]

sorry but no way

[AnonConvert1]

sorry but no way

Okay, I understand this may not be possible with one command per say. But, do you have a sample idea how this could be achieved with multiple commands thrown together?

Here is an example of what I want to achieve.

Sample input:


Sample output: