Generates a gradient between the specified elements, and retrieves the color at the specified point along the gradient, per the index argument.
world.log << gradient("#FF0000", "#000000", 0.5) // outputs #7F0000, as we have halved the red value
Usage:
gradient(Item1, Item2, ..., index)
Item1: Elements of a color gradient list.
gradient(/list/Gradient, index)
Gradient: A color gradient list.
index: The index on the gradient to perform the interpolation on.
Returns:
text: A color, either in #rrggbb or #rrggbbaa format.
