In one example aspect, a method of video processing includes performing a conversion between a current block of a video and a bitstream of the video using a palette mode in which a palette of representative sample values is used for coding the current block. During the conversion, one or multiple predictor palettes are used for predicting the palette of representative sample values, and wherein updating of the one or multiple predictor palettes after the conversion of the current block is disabled according to a rule based on a characteristic of the current block.