1. A method for image coding, the method comprising: obtaining, at a video codec device, an image block for a video frame; generating, by the video codec device, a color index map comprising a plurality of entries and representing the image block, wherein the entries are assigned color indices indicating respective colors; attempting to predict, by the video codec device, a first color index for a first entry of the entries in accordance with a neighboring entry of the first entry in the color index map; in response to successfully predicting the first color index for the first entry, assigning, by the video codec device in a prediction map, a first bit-value for the first entry; in response to not successfully predicting the first color index for the first entry: assigning, by the video codec device in the prediction map, a second bit-value for the first entry; and adding, by the video codec device in a sequence of color indices, an actual value from the color index map for the first entry; and transmitting, by the video codec device to a receiver, the color map index.