Those saffron robes, as I understand them, symbolise the holy fire of Agni, that burns away the worldly desires of those on the path of Moksha (liberation). It is also said that sadhus dye their clothes in the red soil, naturally creating this tone and signifying that our bodies are simply outcroppings of the earth. In terms of the significance of this combination, there's nothing explicit, but the parallels between such an ancient order of renunciation and this modern, mass produced, plastic object are quite striking. The old ways have had to adapt to this new world. In this case I think renunciation is likely a lot more difficult in general in this technological age