The Power BI team recently added additional map styles for the Map and Filled Map that make them a more attractive option for data visualization. Alongside the Road and the Aerial themes, Power BI now has options for Light, Dark, and Grayscale. What do these options add, and why should you care?
As I have pointed out before, one of the (now former) “Cons” of using the out of box Map and Filled Map visuals was that the data could often be difficult to distinguish from the background when using the Road and Aerial styles. The presence of too many colors in the available backgrounds helps to drive the viewer’s focus away from what’s important–the data overlaying the map. It’s helpful to see roads and other features as reference, but to make them nearly visually equivalent to the data by having them vibrantly colored can sometimes be frustrating.
Take the following two examples using the Road style, which has driven both the Map and Filled Map since Power BI was released. In the Map of Washington DC, the purple points are distinguishable from most background colors, but the bubbles also match the major arteries in the road network. More effort is unconsciously required by the viewer to interpret the data toward the southern end of the map due to the color collision. Now imagine that this map included categorical points with many colors (or worse, the infamous Power BI Pie Points!). A similar effect occurs when using the Filled Map, particularly when the color saturation leads to many lighter colors. This effect is not as noticeable at the world level unless you are using blue as your primary color, but zooming in even a little severely reduces the number of colors available to plot data that can be easily distinguished from the base map.
Aerial is not much better because of the greens and blues in the background. Particularly with the Map of Washington DC, it is even more difficult in Aerial to view the points than in Road.
The new Light option is effectively Road Junior. It’s still not a great option if you want to minimize the effect of the background compared to the data.
Coming to Grayscale and Dark, however, we get to my two new favorite styles and the ones that I wish Power BI had offered since its inception. Most color options will not clash with these two styles, which both allow viewers to more easily recognize the data that’s important. For the sake of my eyes and those of countless other viewers, please use these new styles in your reports and let the Power BI team know how thankful you are for adding them!