Each style has its own specific color scheme, but you can always recolor objects to your liking or to fit your brand colors, or whatever.

To recolor an object:

1. Select the object.
2. Click the pallette button to the right of the bounding box. A color picker shows up.
3. At the top bar of the color picker, select the color you want to adjust.
4. Set the new color.
5. Repeat steps 3 and 4 as needed.