When I haved converted a 16 pixel x 16 pixel 24 bit full color bitmap file ( 822 bytes ) to RGB raw file using XnView 1.99,
the output file is a single channel raw file with the size of 256 bytes, which should be 768 (16 x 16 x 3) bytes.
I have already confirmed the channel type of the Raw option is set to RGB in the tab of [Tools]-[General]-[Read/Write]-[Write].
I think it's a bug.
XnView 1.98.8 also can't do it.
XnView 1.98.5, however, can do it correctly! No problem.
Please check it.