Hide column header on table

Hi, tomgramling 

Here is a demo.

pbix attached

If help ,try steps as below.

1.change the field formatting of "Month name" as below

(make sure "apply  to head" is  enabled)

2.Then  change the conditional formatting as below

3.The result will show as below

If it doen't meet your requirement ,you can  refer to other related posts.

https://community.powerbi.com/t5/Desktop/Hide-Table-column-header-when-applied-condition-formatting/m-p/799613

https://community.powerbi.com/t5/Community-Blog/Table-Headers-Conditional-Formatting/ba-p/702522

Best Regards,
Community Support Team _ Eason