Windows 7: How to change the color of system tray arrow?

I would like to change the color of system tray arrow from white to black (in the right corner of the taskbar, when you press it, it shows hiden system tray icons). I have Windows 7 Style Builder, but can't find this option. Can anyone help?

That is at Taskbar & System Tray > System Tray > Basic > Horizontal > Button
and
Taskbar & System Tray > System Tray > Basic > Horizontal > Button:Open

Jerry

Thank you for your answer.
Could you tell me after I go to "Button" and "Button:Open", and choose "color" under the "Type" menu, what should I choose under the "Property" menu? And will it work if I go to "Aero", since I'm using Aero theme?

You cannot change the color of that arrow by adding a color property, you need to edit the image by clicking on the Edit button in using a image editor to change the color.
If you have not set your image editor yet here are some screenshots that may help you (I used gimp as the example if you use a different image editor you will have to navigate to its .exe)

Jerry

Thank your very much for your help, it works!
Just one more question, is it possible to have changed color of arrow with Aero theme or is it just for Basic theme?

You're welcome
Some parts of the Aero theme use some of the basic images.

Jerry

Great, it also works Aero! Thanks again