Adding a Spot Color Channel to .Tiff Images with Python

Question

Im searching for a Solution to Automate some UV-Printer Tasks from Images that are allready processed trough Python and Uploaded to Dropbox. Everything exept the Part of adding a new Channel to the .tiff File. Basicly the Transperancy of the Image should be unchanged, just another Channel in full red should be added on top of the all colors that are in the Image.

On Photoshop you would Mask the existing Elements, create a new Channel and fill the empty mask from the Images Elements Refference with red, so that the Channel is right behind the Text and not visible.

I have found some Code, but im not quiet sure if this brings me to the Solution i need. Maybe somone has more expertise on that topic and could help me out and maybe edit and improve the code for it, to have a final solution. I would appriciate anything!

Things i have found are:

from PIL import Image

def add_spot_color_channel(input_file, output_file, spot_color, region_coordinates):
    # Open the existing TIFF image
    image = Image.open(input_file)

    # Convert the image to RGBA mode
    image = image.convert("RGBA")

    # Extract the alpha channel
    alpha_channel = image.getchannel("A")

    # Extract the RGB channels
    r, g, b = image.split()

    # Create a new channel with the spot color
    spot_color_channel = Image.new("L", image.size, 0)
    spot_color_channel.paste(spot_color[0], region_coordinates)  # Assuming spot_color is a tuple (R, G, B)

    # Combine the new spot color channel with the existing RGB channels and alpha channel
    new_image = Image.merge("RGBA", (r, g, b, alpha_channel, spot_color_channel))

    # Save the result to the output file
    output_file = output_file.replace('.tiff', '_with_spot_color.tiff')
    new_image.save(output_file)

# Example usage
input_file = "existing_image.tiff"
output_file = "image_with_spot_color.tiff"
spot_color = (255, 0, 0)  # Red spot color
region_coordinates = (100, 100, 200, 200)  # (left, top, right, bottom)

add_spot_color_channel(input_file, output_file, spot_color, region_coordinates)

enter image description here

https://www.dropbox.com/scl/fo/nelrijhsdqfmkc6n4ez26/h?rlkey=qwyuzhob8a6llxl2awr50tjz5&dl=0