You can either choose to select a premade category or create your own new category.
If you want to edit a category, scroll down to the category and click on→ Edit category. You can change the name of the category and select a new color. Afterwards click on → Save.
If you would like to create your own category, you can simply write the name of the category in the grey text field and press ‘enter’ on your keyboard. The new category will be saved and a random colour will be assigned. If you like to change the color of your new category, click on → x, scroll down to the category and click on click → Edit category again. Now you can select a different color and → Save your changes.