I remember reading about a very limited palette of colors that apprentice painters would use in the 16th century ishly. Apparently, it was made of readily available, cheap pigments, which is why an apprentice would use it. However, lots of color was possible by intelligent mixing. I can't think of its name and now any googling turns up nothing.
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.