Vaadin Grid Row Hover Style

I'm using Vaadin grid 1.2.0 with Polymer.  I see that the API already provides several custom styling mixins for cells, selected row cells, striped row cells, etc.  However, we were wondering if there was a way to either change or disable the background color when hovering over a row in the table.  Currently, vaadin-grid defines this styling on lines 306-308 of vaadin-grid.html:

tbody:not(.touch):not(.scrolling) .vaadin-grid-row:hover td {
    background-color: #eeeeee;
}

Is it currently possible to access/modify this from within a parent Polymer component?  I've tried something like:

vaadin-grid:hover {
    --vadin-grid-selected-row-cell: {
        background-color: white;
    }
}

but it doesn't have any effect.