@alemoy: For detail color options, you can upgrade to Catch Kathmandu Pro theme and then you can change it yourself from “Appearance => Theme Options => Color Options”.
For free version, you need to do it manually.
1. To delete the border around sidebar widget, then you can add the following css in “Appearance => Theme Options => Custom CSS” box:
#secondary .widget { border: none; box-shadow: none; }
2. To change the footer background color, you need to edit the color code in the following css and then add it in “Appearance => Theme Options => Custom CSS” box:
#site-generator { background-color: #1b5f7d; }
3. For menu, I need more details. So, can you send me your site URL and let me know the detail color code for it and for spaces too.