A method and apparatus of valuing contrast of representation on background displayed on a screen of a navigation apparatus, by counting a number of the presentations on the background of the screen, adjusting contrast of the representations against the background displayed on the screen in response to the number of the representation on the background, and displaying the representations on the screen based on the adjusted contrast of the representation. The contrast of the representations against the background is set lower than original contrast against the background when the number of the representations is equal to or more than a predetermined number. The contrast of the representations is set higher than current contrast when the number of the representations on the screen is less than a predetermined number.