In which situation can hue contrast exist while value contrast remains low?

Correct answer: Red and green of equal lightness

Hue identifies the colour family, whereas value describes relative lightness or darkness; they must be judged separately. Red and green are clearly different hues, but if adjusted to equal lightness their value difference can remain small. Thus option D is correct. Black and white show strong value contrast, light yellow and dark violet also differ greatly in value, and white with light grey has little hue contrast.