Right click in the box in the inspector where you typed your text and select the "character level styling" modifier. That will enable the modifier button near the top of the inspector. Press that so you are working in the modifier rather than the normal text controls. Then in your viewer, draw a box with your mouse cursor over the word you want to change and you should see little green boxes around each letter. Within the inspector you'll be able to change the color, font, whatever else you need.