How to Set up / Style back ground theme / color to the widgets in kibana 4.1
Out of the box, there is only one theme currently shipping with Kibana 4, which is the light theme. We are tracking an enhancement to add other themes, including dark, in the future - so feel free to comment or +1 this issue: https://github.com/elastic/kibana/issues/2906
In the meanwhile, if this is important to you, the visual theme for Kibana 4 is something that can be modified directly in the source. We use Bootstrap with LESS, so you can look at files in this folder if you want to create an alternative theme: https://github.com/elastic/kibana/tree/master/src/kibana/styles/theme