With ‘Note’ I assume you’re referring to the note model element which can be used within the UML diagrams, right?
You have 2 options.
One is to use the Styles feature; this allows you to define the layout of a model element and then apply that to whatever elements you want. You can find this option in the ‘View’ tab (‘Styles’).
To set up such a style you’d use the ‘Format’ option (right click on a model element and select 'Styles and Formatting => ‘Formats’ or click the Format option as found on the ‘Diagram’ tab). This allows you to save your current entry as a new style which you can then use with the Styles menu mentioned above:
Once you have defined a few Styles you can then apply those on any element you want:
Note that you can easily import styles which were defined in another (external) project.
Also: if you want to you can get easier access to this option by assigning it to a specific keyboard combination or by using the Dash menu. Won’t elaborate on that here (post is long enough as it is) but if you’d like more info just ask, I’d be happy to share later.
Second option would be to use the ‘Shape legend’ feature, available in the Standard Edition (and up). See this link (scroll down to ‘shape legend’).
This allows you to simply pull in shapes (and colors) and apply those as you wish.
Hope this could help!