Category Nuances for gray:

• neutral,
• riparian,
• dark,
• upland,
• solid,
• base,
• lighter,
• polished,
• light,
• wild,
• single,
• soft,
• evil,
• pale,
• several,
• common,
• basic,
• sensitive,
• darker,
• native,
• unusual,
• colored,
• natural,
• migratory,
• large,
• unfamiliar,
• opaque,
• insectivorous,
• uniform,
• muted,
• traditional,
• larger,
• distinct,
• marine,
• pastel,
• mutagenic,
• standard,
• local,
• working,
• alien,
• new,

Simple Categories for gray:

• system,
• attribute,
• agent,
• animal,
• color,
• group,
• neutral,
• coating,
• style,
• carnivore,
• beast,
• entity,
• fabric,
• creature,
• mammal,
• tint,
• bird,
• shade,
• predator,
• force,
• institution,
• dress,
• race,
• object,
• horse,
• surface,