The Stout Google Calendar plugin by stoutdesign allows you to easily add and customize embedded Google Calendars to your WordPress site. You can even change color settings that are not normally modifiable, allowing you to seamlessly integrate Google Calendars into the look of your site. No more ugly Google Calendars!
Customize the color scheme of embedded Google Calendars
Options from the Google Embeddable Calendar Helper can be modified directly within the WordPress Admin
Save multiple calendars, each with it’s own color scheme, size and display settings
Display calendars in a Widget, Pages or Posts via shortcode or in templates
Live preview of all changes to a calendar as you make each change
Easy color picker or directly input hexadecimal color values
Download and info: http://wordpress.org/extend/plugins/stout-google-calendar/