How can i change the css property of an element using protractor?

[Bandari-A]

   #  **var element = element(by.model('test')).getCssValue('background-color');

    expect(element).toEqual('rgba(255, 0, 0, 1)');**

   Output: output of above expectation is True.


  # I want to change the new background-color to above specified element.
  # How can i set the new  background-color to above specified element?

  Thanks in advance