def draw_box(image, box, color):
    """Draw 3-pixel width bounding boxes on the given image array.
    color: list of 3 int values for RGB.
    """
    y1, x1, y2, x2 = box
    image[y1:y1 + 1, x1:x2] = color
    image[y2:y2 + 1, x1:(x2+1)] = color
    image[y1:y2, x1:x1 + 1] = color
    image[y1:y2, x2:x2 + 1] = color
    return image