Can we add multiple data colors to visuals through JSON?

Hi Anonymous ,

Thanks for reaching out to us with your problem. Base on your description, you are building a bar chart visual. And you want to get the gardient colors for each column through json theme. Base on my research, there isn't a direct way to apply gradient colors to individual columns in a bar chart using JSON theme files in Power BI. The JSON theme functionality in Power BI allows you to define a consistent set of formatting choices, such as colors for your chart series, background, and fonts, but it doesn't support gradients for individual data points or columns within a visual directly.  However, you can refer the following link to specify an array of colors that will be used across different data points within a visual. 

powerbi - Apply different different data colors to different charts in power bi theme creation - Stack Overflow

{
    "name":"MyTheme1",
    "dataColors":["#ff5624", "#21ff13", "#0009db", "#fff780", "#d3d3d3", "#7d00b6"]
}

Then refer the following links to apply the JSON theme to your Power BI report:

Import custom report theme files

Import Color Theme & Color Theme Generator - (powerbi.tips)

Best Regards