I did that too, but it results in an improper conversion (which has nothing to do with that class. Can you see the difference in the homepage? To see what I mean:
templates/ja_company/local/less/themes/"templatename"/variables-custom.less
This file is NOT being embeded in the conversion. That is why it throws an error. I am not aware anymore, but aint that a file made by theme magic? I tried to copy its content into the template.less, and try it again, but it does not work.