如何在Vaadin 8中有条件地为网格行着色？

我想根据单元格的值更改Vaadin网格行的颜色。我尝试了如下，但没有工作。

断续器

@import "mytheme.scss";
@import "addons.scss";

// This file prefixes all rules with the theme name to avoid causing conflicts with other themes.
// The actual styles should be defined in mytheme.scss

.mytheme {
     @include addons;
     @include mytheme;

     .v-grid-row.error_row {
            // Tried following elements and didn't work.
            // background-color: red !important;
            // color: blue !important; // This changed the color of the font.
            background: green !important;
     }
}

Java Code

grid.setStyleGenerator(t -> {
            if (t.getLogLevel().trim().equals(ERROR) || t.getLogLevel().trim().equals(WARN)) {
                return "error_row";
            } else {
                return null;
            }
        });

注意：我从浏览器的开发人员工具中检查了css，这表明css已正确更新（见下图）。