For changing colour, click on "CREATE". For clearing, click on "CLEAR ALL". For seeing lines which go to mouse pointer, click on "SHOW LINES". Note-For clicking on buttons present on the project, press space which stops the lines and click the button.
I saw TheNothingreal's project and decided to make it. The save and load option is not so good. TheNothingreal's project- https://scratch.mit.edu/projects/406893529/
