Unlike all other drawing commands, the color supplied to C2D_TargetClear must be in the format of the texture being cleared. This is particularly troublesome with 16 bit (RGBA5551) textures, as knowledge of the byte endianness of the system (among other things) is necessary in order to get C2D_TargetClear to function properly. For instance, I currently have to perform transformations on the colors produced by C2D_Color32() to get it into 0bGGBBBBBARRRRRGGG0000000000000000 format solely for this function.