Well, it seems kind of obvious to me, but the word 'spice' should tell you what's wrong here. The reason that Europeans went looking for spice was that their food was bland (or so they told me in school); using a single flat color is going to make things bland. You want to keep things minimal, and that's cool and I respect your artistic license, but it's totally possible to cross the line from minimal to indecipherable-- like the problem of drawing a polar bear in a blizzard. Ultimately, you're either going to have to use a little more color or add a little more detail in some way in order to make it clear that I'm looking at a bed and not a well, for instance.
