How to create simple color gradients in MS Paint.
Step 1: Open Paint
Open paint. It is located under "Programs" and then "Accessories". After you have Paint open, press Ctrl+E. This will open the Attributes window (Attributes can be found under 'Image' too). Set width to 100, and height to 500. (Height can be any number, but 500 works well.) Make sure 'Pixels' and 'Colors' is checked and click OK.