Slide the slider, start x, end x, size, and 3 color values are explainable.To change colors, click the "change color" button, and the output shows the value of the slider 1 to 100.
Default colors are default Scratch 3.0 slider colors, as you may see. To use this, backpack the slider sprite, and use start x, end x, inner circle color, filled outer color, non-filled outer color, length, and slider y to customize your slider.