Thanks Carrie for your great comment 🙂
As for changing the colours, you can yes, but this one you will need to create custom CSS to change the elements that have those colours. You have a few options of doing this:
1. child theme and do the modifications in its style.css
2. Simple custom CSS plugin which creates a separate stylesheet with your changes
3. If you use Jetpack, use the Edit CSS feature to do this
As for your other question…sorry but the RTF file format isn’t opening. Best to do a screenshot as a jpg or png. If I understand you correctly, you want to “center” the content in each box?