I think it looks wonderful

I agree.. the tavern would be mostly wood, and so it would be very brown. But... Most wood, for construction/containers/furniture, in a medieval-ish era (or even up to around the 1900s in poorer areas) will be made from a single type of wood - usually the cheapest available.

Wood like that is easily stained and discolored. Many types of wood, depending on their usage, can range from a deep black, to almost white.

Additionally, there would be layers of grime in less trafficked (and therefore less often cleaned) areas, making deeper shadows, and, by contrast, brighter highlights in other areas.

In the rooms, blankets would be furs (think more reddish browns or blacks) or undyed coarse wool (gray by nature/ yellowed by use) in poorer establishments, or, in more well-off establishments, vibrant colors and rich brocades (or fabrics dyed to look that way).

So you *could* add a lot of color and contrast if you wished to.

I think the lack of objects (plates/mugs/stray pair of boots/etc) also contributes to the *sameness* others may have noticed.

That being said, it does look fine, and if it looks great printed out, and you don't feel it needs any improvement, you should leave it as is.