input: Write a function to format a given piece of text (input) with different options for font-style, size, and color. The function should return a string formatted as an HTML `<span>` element with the specified font, size, and color. If no options are provided, the default font should be "Times New Roman", the default size should be '14px', and the default color should be '#000000'.
  
  def format_text(text, font="Times New Roman", size='14px', color='#000000'):
    return "<span style='font-family: {}; font-size: {}; color: {};'>{}</span>".format(font, size, color, text)
  
  assert format_text('Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer ut lectus vel nisi consequat bibendum ac a erat. Aliquam non velit sit amet arcu placerat vulputate a ut nibh.')=='<span style=\'font-family: Times New Roman; font-size: 14px; color: #000000;\'>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Integer ut lectus vel nisi consequat bibendum ac a erat. Aliquam non velit sit amet arcu placerat vulputate a ut nibh.</span>'
  assert format_text('Colorful text', size='20px', color='#FF5733')=='<span style=\'font-family: Times New Roman; font-size: 20px; color: #FF5733;\'>Colorful text</span>'
  assert format_text('Special font', font='Arial', size='18px')=='<span style=\'font-family: Arial; font-size: 18px; color: #000000;\'>Special font</span>'
  assert format_text('Default settings')=='<span style=\'font-family: Times New Roman; font-size: 14px; color: #000000;\'>Default settings</span>'
output: def format_text(text, font="Times New Roman", size='14px', color='#000000'):
    return "<span style='font-family: {}; font-size: {}; color: {};'>{}</span>".format(font, size, color, text)