title: vis.js timeline set custom background color on items without overwriting borders
body: <p>I'm using vis.js timeline and I'm trying to find a way to mark workhours (give them a different background). Using the <a href="http://visjs.org/examples/timeline/items/backgroundAreasWithGroups.html" rel="nofollow noreferrer">backgrundareas with groups example</a> I have managed to get my workhours colored for specific dates.</p>
  
  <p>I do not want to use the standard blue color for background, so in order to avoid this I add a class workhours. Then I can set my custom color, but then the borders of the cells are hidden unless I also set a opacity less than 1.</p>
  
  <p>I have a color scheme which I'm using, so setting opacity changes the color and my workhours does not look the same in the whole application.</p>
  
  <p>I'm using this code</p>
  
  <pre><code>.vis-item.vis-background.workhours {
      background: ##AFD9FE;
      opacity: 0.75;
    }
  </code></pre>
  
  <p>and where filterFromdate is my start date, durationDay is numbers of days in my timeline and startHour and endHour defines my working hours</p>
  
  <pre><code>  for (i=0; i&lt;durationDays; i++) {
          items.add([
              {
                  id: "W"+i,
                  start: moment(filterFromdate).add(i, 'days').hour(startHour).valueOf(),
                  end: moment(filterFromdate).add(i, 'days').hour(dayEndHour).valueOf(),
                  className : 'workhours',
                  type: "background"
              }
             ]);   
        }
  </code></pre>
  
  <p>this give me</p>
  
  <p><a href="https://i.stack.imgur.com/s9GMJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s9GMJ.png" alt="enter image description here"></a></p>
  
  <p>Can anyone tell me how to either get my class workhours to behave like a standard vis background class (like vis-today)?</p>
  
  <p>or if there is another approach to handle background on specific hours (or days)?</p>