Tone Delta Pair
Documents a constraint in tone distance between two DynamicColors.
The polarity is an adjective that describes "A", compared to "B".
For instance, ToneDeltaPair(A, B, 15, 'darker', stayTogether) states that A's tone should be at least 15 darker than B's.
'nearer' and 'farther' describes closeness to the surface roles. For instance, ToneDeltaPair(A, B, 10, 'nearer', stayTogether) states that A should be 10 lighter than B in light mode, and 10 darker than B in dark mode.
Parameters
The first role in a pair.
The second role in a pair.
Required difference between tones. Absolute value, negative values have undefined behavior.
The relative relation between tones of roleA and roleB, as described above.
Whether these two roles should stay on the same side of the "awkward zone" (T50-59). This is necessary for certain cases where one role has two backgrounds.