In accordance with one embodiment, a color erasing apparatus comprises a reading section, a storage section and a control section. The reading section reads an image formed on a sheet to acquire image data. The storage section stores the image data acquired by the reading section. The control section determines whether or not there exists a mark in the image data, and carries out a control to, in a case in which there exists a mark in the image data, delete the image data read by the reading section from the storage section if it is determined that there exists a mark and the image data acquired by the reading section coincides with the image data stored through the processing of an image forming apparatus when determining whether or not the image data read by the reading section coincides with the image data stored in the storage section in advance, or store the image data read by the reading section in the storage section if it is determined that the image data doesn't coincide with each other.