After further consideration I think it's the background that makes picking a good color for your data bars/lines. The y-axis data labels are in the black part, and the data is in the red part. So you need 2 colors that contrast on both black and red...now that's a challenge. Maybe if you pull back the vignette so there is more red, you can choose collors that contrast well to red. Making the red a bit less bright would also make it easier for your data colors to pop. You can use an online tools to help you pick colors (color contrast checker, lookup color themes for websites etc.).

This community has given me great inspiration to create better looking graphs. It takes some time to consider things like color, but it makes the graphs som much more appealing.

I like that you both show the amount of bands and the 'concentration' of bands per country. Like the other comments said, the chart doesn't read intuitively and it seems like something is off...I'm just not sure how to improve it (not really helping, I know). I like the red and black background, but the data colors (blue and orange) don't really work well with the background in my opinion. Matching the label colors of the y-axis to the data label is a neat trick to quickly see what goes with what. I will use that too from now on!

Hi there, really nice visual you made here. Easy on the eyes and easy to read and interpret the data. Good job!

I have recently posted a visualisation made with Power BI if you want to take a look. I think the standard look of power BI charts is not suited for scientific publications, but you can have a look nonetheless. It might be customizable enough.

I've hear some good things about the Google Analytics course (hosted on Coursera). I myself have done a Power BI Course through my company but there is also a free one to follow online on learn.microsoft for Power BI training. I must say that the visualisation is the flashiest but easiest part, gathering, cleaning and thinking of how to present data is the hard part!

Do you mean like a heatmap? like a table heatmap?

I use Power Bi and Excel's Power Pivot (because my company just looooves Excel). Power Bi is definitely more business oriented and more meant for interactive dashboards. But I just love the graphical interface of it. I am a programmer as well but just hitting buttons is so much easier when visualizing stuff. I think Python and R are definetely more powerful, versatile and customizable. But the ease of use of Power BI (and even Excel) as a visualisation tool are a big plus for me.