Is it possible to change the colors that odoo assigns to the events, to the colors we want?

right now odoo assigns defalut colors to the events like this https://i.imgur.com/wkah1J7.png?1, and i need to assign certain colors :

red to cancelled / green to available  and so on..

If so, how do you it? It's only needed to change the css color assignment, or do we have to change js funtion _getColor()?

Thanks!