Arcade Expression for Label Halo Color

Question

I am trying to label Census Block Groups and Tract ID for the block group feature layer. I would like to label them using different color halos. Is there an arcade expression that will allow me to change the color of the halos for each label in a feature?

So far, I have been able to change the color of the text for the labels but not the color of the halo.

"<CLR red = '0' green = '197' blue = '255'>" + 
'Tract ' + 
"<BSE>" + $feature.TRACT + "</BSE>" +
"</CLR>" + 

TextFormatting.NewLine + 

"<CLR red = '223' green = '115' blue = '255'>" + 
"BG - " + $feature.BLKGRP + 
"</CLR>"

From the image below, I basically want to invert the colors of the halo and the text.

Answer 1

I may be wrong but I do not believe Halo is a property you can alter with HTML tags as described in the help file.

What you can do is create classes of labels, each with their particular halo characteristics. You add a new class under the dropdown from here: