DevTools: render category filters in a way that they don't clash.

Source/devtools/front_end/timeline/TimelinePanel.js

Index: Source/devtools/front_end/timeline/TimelinePanel.js
diff --git a/Source/devtools/front_end/timeline/TimelinePanel.js b/Source/devtools/front_end/timeline/TimelinePanel.js
index dcd3434551c0eb4b0b5fcb0808b76c759631edad..ec4b86bef417228f7a13e0a7de6613d2326efc8e 100644
--- a/Source/devtools/front_end/timeline/TimelinePanel.js
+++ b/Source/devtools/front_end/timeline/TimelinePanel.js
@@ -414,6 +414,7 @@ WebInspector.TimelinePanel.prototype = {
             if (!category.visible)
                 continue;
             var filter = new WebInspector.CheckboxFilterUI(category.name, category.title);
+            filter.setColor(category.fillColorStop0, category.borderColor);
             this._filters._categoryFiltersUI[category.name] = filter;
             filter.addEventListener(WebInspector.FilterUI.Events.FilterChanged, this._categoriesFilterChanged.bind(this, categoryName), this);
             this._filterBar.addFilter(filter);