It looks like you want to remove the category bar graphic a well - at present there is a pale brown gradient bar for all categories ( or whatever colour/s you set them).
But I can't see your graphic method working with this gradient design.
Are you certain you want to remove all text? Sometimes graphics don't display properly for all kinds of reasons not least users with bad config on their browsers which does happen. Some use advert blockers that cut out other images as well - they tend to be crude.
I tend to think it's safer to have a text option to cover all situations like graphic failure. You could use the cat description for this, keep it very short to a word or two. It shows in small text which wouldn't detract frrom your image./
Jake Bunce is the resident wizard here for category bar design. He is so busy he doesn't take private Conversations but you can find his threads and ask him on there.
Try a search on Jake Bunce category - there are several threads that are useful.