You can control the appearance of objects by assigning the colors from the Colors palette.
To display the palette use the correspondence Colors option from
the Object Properties panel. You can control the colors of the object border, fill,
gradient, shadow, tex, and image tint color.
To change the color of the text in a rectangular or an oval, click the object with the Text tool, or double click on the object, select some text, display the Color palette, and, and select the desirable color.