Modifiers matching neutral:

• dark,
• natural,
• earthy,
• warm,
• pale,
• abundant,
• soft,
• small,
• energetic,
• impartial,
• urban,
• new,

Simple categories matching earthy:

• metal,
• constituent,
• tone,
• substance,
• material,
• character,
• food,
• matter,
• item,
• pigment,
• veggie,
• vegetable,
• neutral,
• stone,
• ingredient,
• component,
• aroma,
• red,
• elements,
• scent,