As another follow up to this, when writing my Visual Studio extension, I really wanted to have my tool window appear as much like a Visual Studio window as possible. At times, I found it incredibly difficult to find the correct EnvironmentColors value. At a minimum, the correct color value should work across the default/provided Visual Studio themes. So, frustrated, I wrote a little application to help me figure out the right value, which I’ve made available at http://niahtextfilter.com/environmentcolorsfinder/. To use it, you specify the RGB color value that you want, and the application will display the most likely EnvironmentColors candidates. To get the most accurate candidates, you can provide the color you want to display per theme (dark, regular, blue) - this is easy to achieve if you take a screenshot of a sample Visual Studio UI element in each theme, and color drop the pixel you need.
It helped me match my tool window to Visual Studio reasonably well:
Image may be NSFW.
Clik here to view.
I hope it helps others too!
