code: function needleStyle(context, options, length, isRight) {
      return options.colorNeedleEnd ?
          drawings.linearGradient(context,
              isRight ? options.colorNeedleEnd : options.colorNeedle,
              isRight ? options.colorNeedle : options.colorNeedleEnd,
              length,
              !context.barDimensions.isVertical
          ) : options.colorNeedle;
  }
docs: /* istanbul ignore next: private, not testable 
  Returns needle color style
  
  @access private
  @param {Canvas2DContext} context
  @param {LinearGaugeOptions} options
  @param {number} length
  @param {boolean} [isRight]
  @return {CanvasGradient|string}