I am creating a calendar and cannot find where to change the font or colors in the event itself.
Any help, thanks.

Try the Customize tab (near the top of the page) and then click Color Settings on the right of the resulting page?

devek is correct. Using HTMl you can change font size and color for the window. Do keep in mind that the HTML used will take up space in the "preview window" if you use that feature.
Example:
"This is my first event of the day" will display most of that text, followed by ... at the end for the preview window.
<font size="16" color="red">This is my first event of the day</font> will only display a few letters (no code), but the code will have made up for most of the spaces that the text would have filled. Your preview in the calendar might end up looking like "This i...." because of the HTML coding using up characters of the preview.

I hope I explained that properly. Try it out and see for yourself.
Good Luck