Changing colour of theme – Green Cardobo

Hi I want to use the design layout of Green Cardobo theme for my blog, see here to see what it looks like

https://themes.wordpress.net/columns/3-columns/871/cordobo-green-park-09-beta-09/

I have tried to change the code in theme editor with the code for a light blue shade. When I save the changes and view the blog its exactly the same – all green. What do I need to do, are there certain tags or something else I am missing? The code is definately changed but the colour is the same, thanks in advance.