Code to update hoverer.ts

import {Directive, Component, ElementRef, Renderer, Input} from '@angular/core'
     @Directive({
          selector: '[hoverer]'
          inputs: ['hoverer'],
           host: {
                   '(mouseenter)':'onMouseEnter()',
                   '(mouseleave)':'onMouseLeave()',
            	}
			)

   	 export class Hoverer {
             color: string;
             element: ElementRef;
             renderer: Renderer;

constructor(element: ElementRef, renderer: Renderer)
				{
             this.element = element;
             this.renderer = renderer;
				}
           set hoverer(newColor){this.color = newColor;
			}
	onMouseEnter()
			{
				this.renderer.setElementStyle(this.element, 'color', this.color);
			}
	onMouseLeave()
			{
				this.renderer.setElementStyle(this.element, 'color', "black");
			}
		}