Customizing Flutter widgets using themes

and it's working beautifully as well, … but for the keen-eyed amongst you, … especially those who are designers, … you will have noticed that there is a major difference … between our slider and their slider. … So one of the things is that they obviously … have a white active site … and a gray inactive site, which is very easy to change … so the color of the main toggle, … also changes to the same color as the active track, … which is probably not what you want. … Also, if we look at this one, … that holder, or handle, is much, much bigger … than what we have here, which is a tiny one. … So, how can we make our design look more like this? … Well, if we go over to the documentation … on the slider class, you can see that … we have our usual properties, … which we change, say the "activeColor," "inactiveColor," … and once you get to the bottom the list, … you'll notice that there's nothing that allows us … to just change, for example, the size of that handle, … or the color of that handle, …