slider.fill < layer>

The fill of the slider. The width and height are automatically updated, based on the size of the slider. By default, its backgroundColor is set to #333.
译：滑块的填充。宽度和高度都会自动更新，基于滑块的大小。默认情况下，它的背景色设置 #：333 。

# Create a SliderComponent  
slider = new SliderComponent
slider.center()

# Set the fill color to blue 
slider.fill.backgroundColor = "#28affa"