A display device comprising: an organic light emitting display panel including a plurality of pixels, wherein the organic light emitting display panel comprises a first display part configured to display a first image and a second display part adjoined to the first display part along a bending axis and configured to display a second image, wherein the second display part is bent from the first display part with respect to the bending axis, wherein the first image comprises a first background image and the second image comprises a second background image; and a control module configured to control images displayed in the first and second display parts (FP, BP), to receive a first input image data corresponding to the first background image and a second input image data corresponding to the second background image, to analyze the first input image data of the first background image displayed in the first display part and to generate gradation image data for the second display part, in which at least one of the color, brightness, and chroma is varied, on the basis of the analyzed result, and characterized in that the second background image is a gradation image, wherein at least one of a color, a brightness, and chroma of the gradation image is gradually varied along a direction perpendicular to the bending axis, and wherein the control module is configured to provide the first background image having a first color that is uniform, a uniform brightness, and a uniform chroma to corresponding pixels of the first display part, and the control module is configured to provide the gradation image data to corresponding pixels of the second display part displaying the gradation image on the basis of the gradation image data so that the color emitted by the corresponding pixels of the second display part is gradually varied from the first color to a second color having a wavelength shorter than a wavelength of the first color as a distance of the pixel from the bending axis increases. an organic light emitting display panel including a plurality of pixels, wherein the organic light emitting display panel comprises a first display part configured to display a first image and a second display part adjoined to the first display part along a bending axis and configured to display a second image, wherein the second display part is bent from the first display part with respect to the bending axis, wherein the first image comprises a first background image and the second image comprises a second background image; and a control module configured to control images displayed in the first and second display parts (FP, BP), to receive a first input image data corresponding to the first background image and a second input image data corresponding to the second background image, to analyze the first input image data of the first background image displayed in the first display part and to generate gradation image data for the second display part, in which at least one of the color, brightness, and chroma is varied, on the basis of the analyzed result, and characterized in that the second background image is a gradation image, wherein at least one of a color, a brightness, and chroma of the gradation image is gradually varied along a direction perpendicular to the bending axis, and wherein the control module is configured to provide the first background image having a first color that is uniform, a uniform brightness, and a uniform chroma to corresponding pixels of the first display part, and the control module is configured to provide the gradation image data to corresponding pixels of the second display part displaying the gradation image on the basis of the gradation image data so that the color emitted by the corresponding pixels of the second display part is gradually varied from the first color to a second color having a wavelength shorter than a wavelength of the first color as a distance of the pixel from the bending axis increases.