Sameness (n.) depends on the way of comparing: two facing arrows point the same way to someone thinking of a mirror.
Sameness (n.) lives in peaceful agreement: people hardly ever dispute whether two colours or two rods are the same, and that is the word's home.
Sameness (n.) is indeterminate for colours, and there lie the difficulties Goethe tried to sort out in his theory of colours.
Sameness (n.) of two images: for another's image, the criterion is what he says and does; for my own, nothing — and what goes for "red" goes for "same".
Sameness (n.) is in the eye of the speaker: some say white turned black is essentially the same; others call one shade darker a complete change.
Sameness (n.) splits observers: when white turns to black some say it is still essentially the same, and others, when the colour is one degree darker, say it has changed completely.