Apparatus and method for displaying screen according to degree of strength of brightness of outside linght

PURPOSE: An apparatus and a method for displaying screen according to degree of strength of brightness of outside light are provided to enable a user to recognize a screen clearly regardless of high brightness of the external light by improving the visibility of the screen. CONSTITUTION: A measuring sensor(140) measures the intensity of the brightness of the external light. A display unit(120) displays the display data. A controller(100) compares the intensity of the brightness of the external light measured by the measuring sensor with the preset intensity of the brightness of the external light. The controller sets the color attribute value that has more than one attribute values comprising the display data higher than the preset value, according to the comparison result. The controller changes one of the preset color attribute values into the contrasting attribute value. The controller displays the changed attribute value using the display unit.