I am looking for help on how to adjust the color channel levels of a black and white (or grayscale) image. In photoshop this feature is called the Black and White filter.

The examples below demonstrate my process. The red shirt (which is a perfect mid-gray) is black in the final image. 

**Original Image**
![enter image description here](https://i.stack.imgur.com/QW5M0.jpg)

**Changed Hue to Green**
![enter image description here](https://i.stack.imgur.com/1MD1H.jpg)

**Final Image Now Black and White** (with mid-gray/red shirt black)
![enter image description here](https://i.stack.imgur.com/UY8Go.png)