In this study, a simple but important user interface design choice is examined: when marking required-fields in online forms, should GUI designers stick with the often used asterisk that many form design guidelines cite as the de-facto web standard, or should they choose a colored background as a new design solution to visually signal which input fields are required? An experiment with 24 participants was conducted to test the hypotheses that efficiency, effectiveness and satisfaction ratings of colored required-fields exceed those of asterisk-marked required-fields. Results indicate that colored required field marking leads to fewer errors, faster form fill-in in and higher user satisfaction.