To edit the font, style, size, and color of your text in the Web Terminal, go to the Web Terminal pane on the left side of the program. 

Type your text into the text area of the screen. Then, highlight the text you wish to customize and click on the Font, Style, Size, and Color drop down menus above the text field to select your custom options (you could select Arial, 18pt font, Bold, and Red, for example). 

You can do the same thing in each of your Web Terminal tabs (Home, My Schedule, Full Schedules, Rosters, and My Profile).