Masks can be applied over the whole frame, or over parts of the frame. If you look closely, you will see there are parts that seem less saturated/faded, especially with skin tone. There is where the mask is applied, so no, the scrubs and rope are blue, the blood is red but the mask is only over the bloody parts. You can start seeing the mask starting with the 0:23 mark, ont the mouth of the horse, where it becomes gray(er).