def redraw_masks(parent, ypix, xpix):
    """
    redraw masks after roi added/removed
    """
    for c in range(parent.colors['cols'].shape[0]):
        for i in range(2):
            col = parent.colors['cols'][c]
            rgb = col[(parent.rois['iROI'][i, 0, ypix, xpix]), :]
            parent.colors['RGB'][(i), (c), (ypix), (xpix), :3] = rgb
