We proposes an improved color set partitioning in hierarchical trees (SPIHT) algorithm based on multiwavelet. The algorithm converts a RGB color image into the YCbCr format. Clearly, bits assigned to luminance Y plane are twice than that Cb and Cr chrominance planes. A new spatial orientation tree structure is developed between channel planes based on SPIHT coding. We embed multiwavelet SPIHT codes for color images with the re-combined multiwavelet coefficients. The results show that performance of the proposed coding method is superior to SPIHT on 9/7 wavelet.