Customizing Google Calendar Colors

<iframe src="/gcalendar-wrapper.php?src=[google calendar embed url here]" style="border: 0" width="100%" height="600" frameborder="0" scrolling="no"></iframe>

Go to https://calendar.google.com/calendar and get the embed code

Hover to your calendar and click the arrow down symbol. Then click Calendar Settings.
You can find the embed code in Calendar Details

Download the file here https://github.com/tolabl/tsuchiya_HP/blob/master/gcalendar-wrapper.php