There are a couple of options. One would be to use a highlight action. This won't change the colors of the other bars, but it will mute them a bit, which might work for you. Another method is to use set actions (if you're using 2018.3). I actually showed how to do that in the following blog: https://www.kenflerlage.com/2019/01/538-chart.html . If you have some actual data you can share, then I'd be happy to show you how to do it with your data.