Recently I grew bored of my black Dean V bass.
So without much thought I decided to see what the wood was like underneath and then decide either to leave it natural or paint it a color or a design that's a little more exciting.

As I removed the paint I discovered some variations in the wood.

Here is the most extreme example.
http://img177.imageshack.us/img177/6383/dsc0069smallce9.jpg (http://imageshack.us)

Also when I go further down it goes white.
http://img166.imageshack.us/img166/5564/dsc0072smallei6.jpg (http://imageshack.us)


It's definitely one piece of wood, and I think that the yellow part is just something put over the body to make it smooth. And the white bit is the wood under the layer of varnish.

Although I've come here to check with more experienced people than myself.

Would you recommend that I sand it down to the white coloured wood and then varnish or wax it?

i would not sand it down to the "white wood" because by the time you got to it you will have significantly altered the body thickness/shape and therefore function

That finish is probably only several mils thick, say like a couple of pieces of paper. Sanding or stripping it all off won't hurt, or change the dimensions *that* much. that "yellow layer" you are seeing is most likely a pore filler.