I uploaded my company color pallet with this workflow, (I did use a .style file to import so I am not sure if this will help. Also there is an add database options for the 'Favorites" right click) Hope this helps!
go to 'insert' pane and in the style section click on 'import style'
add your .style file and press OK
Go to your catalog pane and you should see your .style file
you will right click on 'favorites' in the left hand 'Contents' pane and click ADD.
Insert your .style file again (I dragged and dropped from the file location because it wasn't showing in my search for some reason)
In your 'Favorite' section in your Catalog Pane and right click on your imported Style and click "Add to project"
Your color pallet should now have it's own section in symbology under colors!
