Modifiers matching neutral:

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

Simple categories matching impartial:

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