key_color_image
Command line app for creating a particular color scale to images
...In addition, the application allows you to set the global alpha of the image, and translate a particular color to a totally transparent alpha (alpha = 0).
You can also disable alpha component, just in case the input image is a .jpg, or there is any restriction that makes the output image from being saved successfully.
If you do not know the color code, you can pass a color: -color input and the application will let you move the mouse on the screen, and when you press return, the color of the mouse pointer will be picked.
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