Remove category from home page

Hello.

On my homepage I have a tile format: http://www.thesoulhouse.net

On each tile there is the title of the post and also the category for each post. Is there anyway of removing the category button from the tiles as this tends to obscure the image.

I’ve tried adding the following into the ‘additional CSS’ in the customiser as per a previous support post I’ve read. However, it didn’t work.

.news-categories {
display: none;
}