In physics, mass is a universal; one unit of mass is the same yesterday as it is today; as it is here or orbiting Betelgeuse; and if we accept the atomistic thesis then this result follows from the invariance of number; as implicitly pointed out in Lucretious On Nature.
Now consider a man holding a red apple; he sees before him a red apple.
Translate him in space; to Mars say; and ask him what he sees before him - it is still a red apple, he remarks (of course the lighting conditions that normatively obtain on Earth have to be set).
Translate him to Alpha Centauri, or to a small comet orbiting Betelgeuse: the same observation obtains; etc, etc.
Consider now translating him in time, to yesterday, or yesteryear or a thousand years ago; and again with the proviso that lighting conditions are made as on earth, he still remarks that the red apple in his apple still looks red, the same colour of red as before.
Thus, redness is a universal; but a universal that is spatial and temporal; and this is in line with Kants thesis that space and time are the conditions of experience.
But is it possible that redness as a universal can be a platonic form/essence (I'm not sure of the correct terminology here)? That is exist outside of space and time?