You need to wire up the props in your SketchPicker. You can see the documentation here: https://casesandberg.github.io/react-color/

In general, when you have some sort of user input (like your color picker) and you want the input to affect your page in some way, you need to control that input with React state. That's described in the documentation linked above.

You should note that the library you use hasn't been updated in five years, so the documentation still uses class components. You can combine your functional components with class components, but you might want to consider finding a library that is maintained.