In Part 1 of this series, you learned how to use some of Power BI’s built-in themes to change the color schemes of your reports. This of course was better than having to manually customize all the elements in your visualizations, but you were limited in the number of themes available.
In Part 2 you learned about Microsoft’s Theme Gallery where 3rd party developers have offered their custom themes, mostly for free, to anyone who wanted to use them. Yes, you had to go through a few more steps, but this opened the doors to dozens of new themes that you could use to add different colors to your reports.
Because these downloaded themes were written in a markup language called JSON, it was possible with a little effort to open these files and tweak the colors to those you wanted. Maybe you did this by trial and error or maybe you found a few websites that tried to explain what the different elements in the JSON file meant. But at the same time, Microsoft was hard at working making it possible to customize more and more of the elements available in your reports. How could you keep up with these changes?
Activating a Preview Feature (After this feature goes live, you can skip this section)
To solve the increasing complexity of building themes, Microsoft decided to add a new feature to help you customize your themes. This feature was first released as a preview in the December 2019 update of Power BI Desktop. Because it was a preview feature, you did not automatically see it in the toolbar. To turn it on, you had to follow these steps:
- After launching Power BI, click the File tab in the main menu.
- In the Backstage Menu, (or left side menu on most systems) look for: Options and Settings and click it.
The right panel displays two menu items as shown below. Click the first one, Options is what we want today.
Selecting this action displays a dialog of available options, but because there are so many, they are divided up by categories which are displayed on the left side. Look for and select the Preview features to see all the current features that are still in preview mode. Then find the ones you want and select them by clicking the box to the left of the feature name. Most of the preview features also have a ‘Learn more’ link that displays a page with additional information about that feature and how to use it.
- When you click Ok to close this dialog, you will probably be told that you have to close the current instance of Power BI and restart it in order to see the selected preview features. So go ahead and do that. I’ll be right here when you are ready to continue.
Customizing the Current Theme.
After you have restarted Power BI, you can now open the View ribbon as you have done before to access the built-in themes and the Theme Gallery. You should now see a new option at the bottom of the Theme dialog that says, Customize Current Theme.
If you click this menu option, a new dialog opens with the title ‘Customize theme’ (shown below) This dialog is a tabbed dialog with the tabs running down the left side. When you click one of these tabs, the options available under that category of theme customizations appears in a second column. For example, in the Name and Colors tab, you see two options, Name and Colors and an Advanced option. Selecting either of these changes the options that appear in the right side of the dialog.
Notice that you can supply a name for the custom theme here and define eight data colors. Why eight? Well I suppose they could have allowed any number, but considering that these colors are used for different data series in line, bar, and column charts as well as each slice of a pie chart, the general feeling is that having too many colors on any of these charts makes it hard to interpret as your eyes will have a difficult time determine slight variations in the shade of similar colors.
There are also what are called Sentiment colors. These colors are used in the key performance indicators and waterfall charts. If your reports do not include these visualizations, you can probably ignore these colors.
Next if you scroll down, you will see something called Divergent Colors. These colors are used as default colors for conditional formatting of data to indicate three possible states, Minimum, Maximum and Neutral (or Middle). Again, if you are not using conditional formatting, you can ignore these colors.
Always be aware of the vertical scroll bar on the right side of this dialog as many of the pages contain more options than can be shown at one time. Also look for and click on small circles with an ‘I’ inside of them as they typically provide a quick definition of features that may not be obvious.
To change the colors in the current theme, click in the color box (on the dropdown arrow or even on the color itself). This opens a color palette dialog like the one shown below. While your eye may be drawn to the large square with various gradients of color, I would not start there. Unless you are trying to match a specific color for which you know the RGB value, I would start with the ‘rainbow’ horizontal line of color hues. You can click anywhere along with bar to select a basic color hue to start. Next, I would look at the large square above and use it to blend in various amounts of white, black and grey to adjust the shade of the chosen color to the one you want. If you know the color’s RBG value, you can enter it directly in the box in the lower left. Note that this requires the hexadecimal value of the color which uses two characters for first red, then green, and finally blue. If instead you know only the decimal values for the amount of red, green, and blue, you will not have to find a decimal to hexadecimal converter. Just enter the decimal values in the three box to the right of the hexadecimal box. Note that decimal values in each of these boxes only range from 0 (#00) to 255 (#ff). [Numbers displayed with a ‘#’ symbol at their start indicate the rest of the number is a hexadecimal number, not a decimal. Therefore #85 is really 133 in decimal.]
When you have the color you want to use, how do you save it? There is no Save or Update button in the color palette dialog. Simply click outside of the dialog and the change will be saved for that color element. Note that the color change will not take effect immediately. In fact, it will only update the current theme colors of your Power BI report when you click the Apply and Save button in the Customize Theme dialog’s lower right. This allows you to select other colors and change them and even go to other tabs in the customization dialog and change other features. In fact, you can cancel your changes to the current theme at any time by clicking the Cancel button. However, this dialog will update the current theme associated with the current Power BI reports as soon as you click the Apply and Save button.
While we don’t have time today to go through all of the features you can customize using the Customize Current Theme tool, you can certainly try them on your own. Just remember one thing. Always save your starting Power BI reports so if you happen to accidentally create and apply a truly horrendous theme to your Power BI report, you can simply exit Power BI without saving your changes and then re-open the original report prior to your most recent theme customizations.
Some of the other things that you can change other than colors within a theme include the font family for the text of different elements, the transparency of some elements, and you can turn on or off borders. If you are thinking that there may still be some things missing that you would like to customize, but cannot, it could be simply that until this feature is out of preview, the Microsoft Power BI team could still be working on it to add more functionality, so be patient. Even after it comes out of preview, if there are elements not included that you think should be, you can always provide that feedback to Microsoft using the ‘Submit an Idea’ button in the Help ribbon.
So this time you learned how to customize the current theme for any Power BI report file and that customization is stored inside the report so if you pass the .pbix file to a co-worker who uses Power BI, they will see your custom colors, not the default ones. Even if you publish your Power BI Desktop report to PowerBI.com, your custom colors will stay with the report. Next time, I will talk a little more about what you can do with your customized theme and why you would do those things.
C’ya next time.