polygon - Changing categorized style color simultaneously in QGIS

I work with this polygon: and i need that all features will be with border line only without fil colors. I seek for a way to do it simultaneously to all the categorized features, and not treat every

polygon - Changing categorized style color simultaneously in QGIS

QGIS no longer loads styles from PostGIS · Issue #39850 · qgis

QGIS for Tableau Users # 5: Outlines, Fills, and Custom Labeling

Randomising colour for many of polygons in QGIS - Geographic

QGIS (SIMPLE STYLE. Change color of Polygon)

How to color polygons based on attribute in QGIS 3.8? - Geographic

2.5. Raster processing — GIS4Schools documentation

Introducing QGIS live layer effects!

Lesson 2 Installing QGIS and Adding Layers (QGIS 3.0) – Geospatial

layouts - Selecting different colors for touching polygons in