Kants theory of space, time and causality is that they are the very forms of experience and ground all the other phenomena that we can experience. He called them the forms of sensibility.
Kant studied at Konigsberg under Martin Knutzen who introduced him to Newtons natural philosophy and cosmology and to which he contributed original theses on tidal locking and the origins of the solar system. Newton notably also wrote on light.
It's startling to first realise that what we experience as the qualia of colour is purely a mental phenomena and does not inhere in the object itself.
This is suggestively close to Kants notion of the qualia of space, time and causality that it is tempting to posit that he may have been inspired by it.
Q. Is there anything which Kant wrote that backs this up, or has this been posited by any commentator on Kant?
It's also worth noting that this may not have been wholly original with Kant. Pythagoras is said to have suggested that we see by something emitted by the eye that illuminates our surroundings. This theory was refuted by Aristotle who wrote that had this been true then we should be able to see in the dark. This is so obvious that one is compelled to rethink what Pythagoras was aiming at with his suggestion and I can only think he means that it is our own sensibility that goes out from us to meet the world and form it for us, in a sense, illuminating it for us. That is, the eye is not a window onto the world through which a vision of the world enters but that our vision of the world is a synthesis of our sensibility which goes out to the phenomenal world and shapes it so that it is rendered intelligible to the mind.