If some of the colors cannot be changed in the Aware IM configuration interface then they can be changed at the .css level or changing the images for buttons and other controls.
The default directory where all Aware IM web resources are is AwareIM/Tomcat/webapps/AwareIM/fw/def (style1) or def2 (style2). If you change files in this directory all applications will inherit the changes.
For each individual application Aware IM copies the default directory into the directory AwareIM/Tomcat/webapps/AwareIM/painter_businessSpace...
So you need to make changes in this directory for an individual application. Mind you, these changes will be lost if you publish a new version of the business space. So either you have to restore the changes afterwards or make the changes after the final version has been published(recommended).
The .css file that affects the color of the alternating rows in the list control (the blue in your example) is in painter../def(2)/style/controls.css - look for the "even rows" and "odd rows" comments and change the background color.
All buttons are in painter.../def(2)/image/buttons directory. You can edit these images and provide your own versions.
Hope this helps.