no, I don't think so.
You could probably create a TextBox like this:
pawsTextBox* label;
csString text = "text";
csRect frame = label->GetDefaultFrame();
frame = label->GetWidgetTextRect(text, frame.xmin, frame.ymin);
label->SetRelativeFrameSize(frame.Width(), frame.Height());
label->SetText(text);
label->SetBackgroundColor(0, 0, 0);
and place it on top of an other widget with a different background color.