Either right-click on the text and choose Outline from the menu that appears, or select the text and then choose Text Outline from the Format menu.
Click the Outlined button so that a check mark appears.
Choose the colour of the outline by clicking the Colour Button 
and then selecting from the 40 standard shades or the colour cube as required.
Choose the width of the outline by clicking the arrowheads next to the Width indication. The maximum value is 50. A preview of the outline appears below.
Click OK to add the outline to the chosen text.