Modifiers matching colors:

• related,
• solid,
• special,
• simple,
• muted,
• positive,
• bold,
• pastel,
• dark,
• intermediate,
• darker,
• bright,
• significant,
• psychedelic,
• warm,
• individual,
• dull,
• over,
• colorful,
• flashy,

Simple categories matching dull:

• object,
• material,
• color,
• surface,
• colors,
• item,
• stuff,
• relic,