shareColors (shareColors) {
        if (!arguments.length) {
            return this._shareColors;
        }
        this._shareColors = shareColors;
        return this;
    }
Get or set color sharing for the chart. If set, the {@link ColorMixin#colors .colors()} value from this chart
will be shared with composed children. Additionally if the child chart implements
Stackable and has not set a custom .colorAccessor, then it will generate a color
specific to its order in the composition.
@param {Boolean} [shareColors=false]
@returns {Boolean|CompositeChart}