Inject Style in Vaadin

InjectStyleInVaadin.java

package TEST;

import com.vaadin.annotations.Theme;
import com.vaadin.annotations.VaadinServletConfiguration;
import com.vaadin.server.Page;
import com.vaadin.server.VaadinRequest;
import com.vaadin.server.VaadinServlet;
import com.vaadin.shared.ui.colorpicker.Color;
import com.vaadin.ui.CssLayout;
import com.vaadin.ui.UI;

import javax.servlet.annotation.WebServlet;

@Theme("mytheme")
public class MyUI extends UI {

    @Override
    protected void init(VaadinRequest vaadinRequest) {

        // Define the custom color
        Color color = new Color(2,3,4);

        // Inject a custom style
        Page.Styles styles = Page.getCurrent().getStyles();
        styles.add(".my-layout { background-color:" + color.getCSS() + "; }");

        // Use the style
        CssLayout cssLayout = new CssLayout();
        cssLayout.addStyleName("my-layout");
        cssLayout.setSizeFull();

        setContent(cssLayout);
    }

    @WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
    @VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
    public static class MyUIServlet extends VaadinServlet {
    }
}