When you have input color and output color and you want to calculate the right `amount` value.

color.py

import subprocess

desired_output = '*{color:#2290f0}'

# Iterate through possible values of 'amount'
for amount in range(1, 100):  # Adjust the range as needed
    # Create the Sass code with the current 'amount'
    sass_code = f'*{{color:darken(#3a9cf2, {amount})}}'

    # Run the Sass command and capture the output
    result = subprocess.run(
        f'echo "{sass_code}" | sass --stdin --style=compressed',
        shell=True,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True,
    )

    # Check if the resulting CSS matches the desired output
    if result.stdout.strip() == desired_output:
        print(f"Found the correct 'amount' value: {amount}")
        break

shell.sh

sudo npm install -g sass