unvarying

形容词 unvarying:

1. persistent in occurrence and unvarying in nature
   同义词：changeless, constant, invariant
2. lacking variety
   同义词：unvaried
3. always the same; showing a single form or character in all occurrences
   同义词：uniform

1. The colours used are flat and unvaried.
   使用的颜色既单调又无层次。