Same Problem Here 
Same problem,
and with the plugin cordova-plugin-headercolor too.
Cordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.4
Ionic CLI Version: 2.1.17
Ionic App Lib Version: 2.1.7
Ionic App Scripts Version: 0.0.47
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v7.0.0
Xcode version: Not installed
Someone opened a task in the xwalk tracker. Seems till yet the xwalk team were unable to reproduce the problem.
Thx the xwalk open tracker i found the SOLUTION!!!
In your index.html file, there is a meta information called theme-color. Per default this value is set to the blue we are all searching to change. Change the value to whatever, it gonna work
<meta name="theme-color" content="#4e8ef7">
The reason: This isn’t a bug but a feature Xwalk implemented to match a Chrome improvements.
See following Xwalk tracker
https://crosswalk-project.org/jira/browse/XWALK-4305
And the blog post from Chrome
7 Likes
It works, thank you …
Just keep in mind, Crosswalk has reached it’s end of support and Intel will no longer be supporting it.