Mess with the Bluemix Colors

The Bluemix designers consider their color scheme: robust, decent and unobstrusive. However not everybody likes the dark colors ( some do). Stylish to the rescue. It comes in Firefox and Chrome flavours. It requires a custom style sheet and it might take you a while to figure things out. So use this for starters:

 .dashboardArtifactCreationSection .tile,
 .cloudOESpaceLabel,
 .tile-container .tile,
 .bluemix-global-header,
 .bluemix-global-header .bluemix-nav-list,
 .NavTree2,
 .cloudOEActionBarDockedNavArea,
 .cloudOEActionBarSelector,
 .cloudOEAppDetails .cloudOEActionBarDockedNavArea,
 .inner,
 .cloudOEAppDetails .cloudOEActionBarNavigationTreeNode,
 .d-category-section .category-header,
 .dijitInputContainer,
 .cloudOEActionBarContentArea .cloudOEFilterBar .cloudOESearchBox .dijitInputField,
 .cloudOEActionBarContentArea .cloudOEFilterBar .cloudOESearchBox input,
 .cloudOEActionBarContentArea .cloudOEFilterBar .cloudOESearchBox .dijitTextBox,
 .d-docked-nav-area .d-nav-container,
 .nav-category,
 .cloudOEAppActivity,
 .appDetailsOverview_Health .tile-segmented,
 .appDetailsOverview_EstimateCost {
    background-color: #3366ff;
    color: #fff;
}
  body {
  background-color: white;
  }
  header {
    background-color: #6677CC;
  }
  
  .cloudOEStoreFront,
  .catalog-message-pane,
  .catalog-container {
    background-color:  #65C4FF;
    color: black;
  }
  
   .cloudOEDockedOpenNav {
    background-color:  #4dc4ff;
     color: black;
   }

Now go and pick nice colors.
As usual YMMV