In Blend I can open the extension Gallery and see almost the same extensions as in Visual Studio. I installed the "Color Theme Editor" in Blend. It installed new Themes, like "Solarized", but the editor itself doesn't work.
I tried another approach, the Extension with Additional Color Themes was also available in Bend, so I downloaded it from here https://github.com/Microsoft/VS-ColorThemes/releases/ and added my own Color Theme. Then I compiled it and installed it. It was installed in Visual Studio but not in Blend?
I tried to understand, what went wrong, but I didn't found the problem. I assumed it has something to do with the target. But the target used was Visual Studio Shell. I assumed Blend is also using the Shell. All other targets where specific versions of Visual Studio. I didn't found Blend there.
I also didn't found anything about this subject in Google. I wonder if anyone can enlighten me a little with this?