Does anyone know how to change the background colour of command buttons. Can this be done by code at all?

You cannot change the back color of the Access command button even with code. It doesn't have that property. The trick is to grab some other button looking .gif, .jpg, or .bmp and paste it into the form. You can then put a transparent button on top of it and get the same effect. I've customized many forms this way and they look very non-Access-y.