Final answer:
The word 'nuance' describes a subtle or minor difference in meaning, tone, or feeling, which in arts, relates to variations in color intensity when white or black is added to a base color to create tints and shades.
Step-by-step explanation:
The word that fits the definition 'a shade or degree of difference in meaning' is 'nuance'. In the context of visual arts, especially when discussing value in color theory, we refer to the addition of black or white to a base color, creating different gradations. When white is added to a color, we produce a tint, which is a lighter version of the color. Conversely, when black is added, we produce a shade, a darker variant of the color. Additionally, we can create a tone by mixing a color with gray, which is often used to achieve subtle shifts in color within a painting for effect and depth.
These changes in color value are not just technical considerations but can also deeply affect the emotional impact of a painting. Renoir's 'Mother and Child' uses many tints for a cheerful effect, whereas Diego Alfaro Siqueiros's 'Peasant Mother' uses shades to evoke a somber mood. The balance of contrast between lights and darks, tints and shades, is essential in creating visually compelling artwork.