Thanks, I saw that option on Kibana 5 yesterday after I wrote the post. Is this feature available on the 4.x branch too? I am using Kibana 4.2.2 and an upgrade to 5.x is not going to happen in the next couple of weeks
However according to this post (Cell Backgroud color instead of field text fore/back color), it is only possible to influence the text background color and not the background of the line itself or at least the cell, which may look kind of poor is the text fields are not the same size 
I think I might go for Option 2.
- Are there any best practices, regarding image type, image size? Do I have to upload the images in the right size, or are they scaled automatically?
- Is it possible to load other stuff, except images (iframes)?
- What would be the best way to serve the Images?
First Option: Let Kibana serve the images
I tried to let kibana serve the files
cp /opt/kibana/src/ui/public/stringify/icons/de.png /opt/kibana/src/ui/public/stringify/icons/test.png
service kibana restart
but when I try to retrieve it, I get an 404 Error
http:///bundles/src/ui/public/stringify/icons/test.png
{
"statusCode": 404,
"error": "Not Found"
}
Second Option: Use the Apache httpd reverse proxy
I am deploying my ELK as appliance-like VM and I want to keep configuration to a minimum (I have no DNS or fixed ip addresses to rely on).
If I define my URL-Template as "http://localhost/images/{{value}}.png" will kibana resolve the address, or is it the browser? Does Kibana have a variable for its ip address?
The only other way I can think of, would be using a relative link and let the reverse proxy do it´s magic
BR