Is there a way to color code events in de default Calender application
Yes you can, you will need to create a different "calendar" (probably "tag" would be a better name, but that's Google's terms for it). 

Creating a Calendar (do this from the Desktop, I didn't found a way to do it from Android's Calendar app; do anyone know?):


Go to http://www.google.com/calendar.
Look for the "My calendars" box on the left, click on "Add"
Fill in the information, and click Create Calendar.
You can change the color later from "My calendars" box, by clicking on the triangular button.




Adding Events to Calendar (can be done from Android):


On the "Create New Event" view, choose the calendar you've just made from "Calendar" combobox.