Change notification area expansion arrow icon

So. I am and have been looking for a way to change the system tray arrow icon that shows you the icons that are in the tray once you click on it I highlighted it in pink. I want to change that icon.

It's part of the Taskbar, I don't think it can be changed without modifying/re-writing the core files of Windows.

The only way to change the default one is to use a third custom theme or edit yourself using windows style builder ( paid software )

Mine is the blue dot on screenshot for example .