How to programmatically change the primary color in Android L?

USe this code for setting toolbarcolor and status bar (darker toolbar color)

toolbar.setBackgroundColor(toolbarColor);
factor=0.8f; 
int a = Color.alpha(toolbarcolor);
int r = Math.round(Color.red(toolbarcolor) * factor);
int g = Math.round(Color.green(toolbarcolor) * factor);
int b = Math.round(Color.blue(toolbarcolor) * factor);
int statusColor=Color.argb(a,
        Math.min(r, 255),
        Math.min(g, 255),
        Math.min(b, 255));
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    Window window = MainActivity.this.getWindow();
    window.setStatusBarColor(statusColor);
}

You can, of course, implement custom subclasses of View that have methods for setting colors.

You can also define multiple themes with you various color schemes.

Views look up theme information from the context when they are created. So to change the styles applied from a theme you will have to recreate your view hierarchy with a context that uses the right theme.

One way to do that, is to create a new ContextThemeWrapper and then get a LayoutInflator that uses that theme wrapper, remove the old version of your layout and re-inflate your layout.

Roughly:

ContextThemeWrapper themeWrapper = new ContextThemeWrapper(this, R.style.AppThemeWithColorScheme2);
LayoutInflater layoutInflater = LayoutInflater.from(themeWrapper);
viewContainer.removeAllViews();
layoutInflater.inflate(R.layout.my_layout, viewContainer, true );

If you are using Action Bar, that may be a bit more tricky, because the Action Bar is created once per activity.