Photoshop new layer is grey

[Roof]

I've got my hand on a couple of photoshop vids and in this video they create a new layer and it looks grey it is transparant but greyish.

Am i able to do this in CS3, i only get transparant and i want to use white on the layer. So this greyish looking layer makes white a lot easier to see

Does this make sense.
Added a screenshot....

Thanks....

[Roof]

found it....

[ricktas]

So how did you sort it out, might be worthwhile posting, so others who want to know, can as well?

[Roof]

yeah should've thought of that....here we go

Edit>preferences>transparency & gamut

something new opens up, the thing you want to change is called grid colours.

I needed it to make smoke and wanted to see the work on the layer.

There you go feel free to thank me now....