Another strange issue, if I set the color from default (in my case white) to say new Color(255, 167, 167), it ignores my color. If I say Color.black (for example) then it uses the color.
Camera.main.DOColor(Color.black, .4f) //will use color
Camera.main.DOColor(new Color(255, 167, 167), .4f) //ignores color, doesn't do anything
(latest Unity, 5.3x)