怎么将资源赋值给绘制的颜色属性，两个类型之间是怎么转换的？

let context = getContext(this)  
  
@Entry  
@Component  
struct fillStyle {  
  private settings: RenderingContextSettings = new RenderingContextSettings(true)  
  private context: CanvasRenderingContext2D = new CanvasRenderingContext2D(this.settings)  
  
  build() {  
    Flex({ direction: FlexDirection.Column, alignItems: ItemAlign.Center, justifyContent: FlexAlign.Center }) {  
      Canvas(this.context)  
        .width('100%')  
        .height('100%')  
        .backgroundColor($r('app.color.backgroundColorCanvas'))  
        .onReady(async () => {  
          const value: number = await context.resourceManager.getColorByName("fillStyle")  
          const fillStyle = '#' + value.toString(16).slice(2);  
          this.context.fillStyle = fillStyle;  
          this.context.fillRect(20, 20, 150, 100)  
        })  
    }  
    .width('100%')  
    .height('100%')  
  }  
}