Adrichem

This week I purchased Affinity Designer. I am trying all options now. Great! But now I tried to make my own brushes. That does'nt work in a perfect way. The brush is made and stored in the category I made, in colour. But when I want to use it, it's only visible in grey. Anyhow I have included a screenshot that I made from the situation I guess I'm doing anything wrong, but what? I hope anyone of you could solve this...