在本例中，采用一个滚动条，两个滑动条，分别赋予了红，绿，蓝三色，通过调节滚动条或者滑动条，来改变背景颜色。-In this case, using a scroll bar, two sliders, and given the red, green, and blue, by adjusting the scroll bar or slider to change the background color.