Change color of window buttons

If you refer to the minimize, maximize and close buttons: yes you can.

You can download windows border themes from: http://art.gnome.org/themes/metacity in which you will find several different styles for customizing those buttons.

If you prefer to use GTK and depending on the theme of your choice, some themes allow you to give a little bit more customization to its items. Simply go to System/Preferences/Appearance and clic on the "Customize" button of the "Theme" tab.

There is also a link which will lead you to the website I suggested above.

Here is a screenshot for you to see what I mean:

Additionally, you can use Emerald theme manager in order to have more stylized windows decorations and a little more control on the appearance of the items.

Simply install emerald and run the emerald --replace command in a terminal in order to change your windows decorator, then open your Emerald Theme Manager on which you will be able to easily manage and edit your themes.

Here is the Emerald theme manager in action:

In the next screenshot, I have changed my emerald theme in order to show you how emerald is handling the buttons that I refer (minimize, maximize, close, etc.) And I am showing the "Buttons" Tab inside of the "Edit Themes" section of emerald theme manager.

Further more, you can also create your own themes both for GTK and Emerald. You may find information on the related sections of the window decorator's website.

I hope this give you an idea and I am sorry if I misunderstood your question.

EDITED:

Well, after watching your comment now I understand what you mean.

For that purpose what you can do is to make a copy of the current png images for the theme you wish to change. "Ambiance" png images are inside of the

/usr/share/themes/Ambiance/metacity-1

This screenshot illustrates what I mean:

So I suggest you to make a copy of those files in a new folder and edit them using your favorite image manipulation program (gimp would be great) in order to change the hue, saturation and other things as you wish.

After that, drop the images back to the original folder but you will be in the need to run sudo nautilus in a terminal in order to be able to "paste" your edited images in the folder. After that you may need to restart (at least the X) in order to the changes to take effect.

In the next image I have opened the "close.png" png image in order to edit it. I am using the selection tool in gimp in order to change the "hue/lightness and saturation" of the selection to a different color. This tool can be reached in the "Colors" menu of Gimp.

Note:

As PNG files open in indexed mode by default, you might want to try converting the PNG into RGB mode (menu Image ➔ Mode ➔ RGB). Then change it using the Hue/Saturation/Value tool (menu Colors ➔ Hue-Saturation) and then converting it back into indexed before saving it.

REMEMBER: To make a backup of your files and good luck my friend!