def color_for (arg)
      arg = Yummi::Context::new(arg) unless arg.is_a? Context
      call(arg)
    end
def color_for (arg)
      arg = Yummi::Context::new(arg) unless arg.is_a? Context
      call(arg)
    end
Returns the color for the given value

 === Args

 A context or a value.