I’ve just had a wonderful discovery about why Power BI sometimes seems to choose random colors in the legend.
Typically, the first item in a series will match the first color of your Power BI theme, the second item in the series will match the second color of your Power BI theme, and so on.
However, this isn’t always the case. I have noticed that sometimes when I have text category values for my legend that Power BI can assign random colors, seemingly not even part of my theme. Until recently, I just accepted this as a quirk of Power BI and carried on with my report development.
Read on for the answer.