You can use the following steps to create your own color styles:
Select the object for which you want to create a different color style
Go to the Properties panel and click on the Styles icon next to the property that you want to save it for
Click on the [+] icon in the Color Styles menu and it will provide you the option of creating a new style
Give your style a name, and press the Create Style button.
Please note: When you create a Style for a Gradient, both the colors and the gradient direction/angle gets saved to the Style.