Modifiers matching neutral:

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

Simple categories matching impartial:

• institution,
• organisation,
• group,
• person,
• body,
• commentator,
• observer,
• professional,
• consultant,
• authorities,
• party,
• entity,
• agency,
• neutral,