--- a/client/src/components/CategoriesTooltip.js	Mon Oct 08 03:30:54 2018 +0200
+++ b/client/src/components/CategoriesTooltip.js	Mon Oct 08 04:09:19 2018 +0200
@@ -50,7 +50,7 @@
           {this.props.categories.map((category) =>
             <button type="button"
               key={ category.name }
-              className="btn btn-primary"
+              className="btn btn-sm text-secondary"
               style={{ backgroundColor: category.color }}
               active={ this.isCategoryActive(category)  }
               onClick={ this.onButtonClick.bind(this, category) }>{ category.name }</button>