The Scratch Cat will ask you to type in the text to be written and give the colour. Pressing the spacebar whilst the program is running changes the background. Pressing the up arrow makes the text bolder; the down arrow makes it thinner. If it takes too long, you can always activate turbo mode (hold shift + click green flag)!
I made the writing look messier so it looked like handwriting, and added a rainbow colour (even though it isn't a colour)