Subtle differences refer to the small, often imperceptible distinctions between two things. NUANCES (7 letters) are slight variations in meaning, tone, or feeling. NICETIES (8 letters) are small details that make something more pleasant or attractive. SHADINGS (8 letters) are subtle gradations of color or tone. Fineline (8 letters) is a very thin line or distinction. All of these terms refer to the concept of subtle differences, which can be difficult to detect but can have a significant impact on the overall meaning or effect.