def color_borders(img, color, thickness=10):
    """Draw a frame (i.e. the 4 sides) of image.

    Parameters
    ----------
    img: np.ndarray
        Input image with shape of (H, W, 3) and unit8 type.

    color: Tuple(int)
        Color to draw the frame.

    thickness: int, default: 10
        Thickness of the frame.

    Returns
    -------
    img_w_frame: np.ndarray
        Image with colored frame.
    """
    assert img.shape[0] > 2 * thickness and img.shape[1] > 2 * thickness, "Image must be larger than border padding."

    img_w_frame = img.copy()
    img_w_frame[:thickness, :, :] = color
    img_w_frame[-thickness:, :, :] = color
    img_w_frame[:, :thickness, :] = color
    img_w_frame[:, -thickness:, :] = color

    return img_w_frame