A method of video decoding performed in a video decoder includes receiving a syntax element from a bitstream of a coded video. The syntax element can indicate that residual blocks of a current coding unit (CU) are processed with a color space conversion. The residual blocks of the current CU can include a luma residual block, a first chroma residual block, and a second chroma residual block. In response to receiving the syntax element indicating that the residual blocks of the current CU are processed with the color space conversion, one of two options of color space conversion equations can be selected. An inverse color space conversion using the selected option of color space conversion equations can be applied to the residual blocks of the current CU to generate modified versions of the residual blocks of the current CU.