I don't know how hard it would be to make the header rows in BlockingDeque presented like the ones in e.g. Deque. Deque uses striped thead, which gets the #DDD background from the stylesheet. And having <thead>s is probably itself an accessibility feature.
table.striped > thead { background-color: #DDD; border: 1px solid black; } we could brute force the same background color or try to convert these to striped tables (but you probably tried that).