What is the name of the palette that apprentice painters would use?
Do you remember if it was referring to a specific technique (such as oil painting) or pigments in general? 

It could be the Velázquez palette*. This is a limited palette consisting of a blue, an ochre and a yellow pigment (with optional black) - for example ultramarine blue, burnt sienna and yellow sienna. With these pigments it's possible to mix a large number of hues (browns, greens, yellows, blues), enough for example to paint naturally looking landscapes. The lack of bright reds might be a limitation for some subjects, but I'd say you could made do if necessary. 

I don't know whether these pigments were sold in sets, but at least both siennas should be really cheap, as it's basically a fancy clay.

The only other named palette I associate with apprentices would be Grisaille, which is a grey/sepia monochrome that was used for value studies and underpainting.



*The linked page is sort of broken; Handprint still uses frames so it's not possible to link to the page properly. Here's the whole palette page with sidebar.