Remarks on Colour line that 'There is no such thing as phenomenology, though there are phenomenological problems.' He was content to regard Goethe's observations as a kind of logic or geometry. Wittgenstein took his examples from the Runge letter included in the "Farbenlehre", e.g. "White is the lightest colour", "There cannot be a transparent white", "There cannot be a reddish green", and so on. The logical status of these propositions in Wittgenstein's investigation, including their relation to physics, was discussed in Jonathan Westphal's "Colour: a Philosophical Introduction" (1991). Although "Remarks on Colour" is considered difficult on account of its fragmentation, his last work,
Isabelline (colour) form of leucism caused by a uniform reduction in the production and expression of melanin resulting in areas of plumage on the back of the bird, normally black, being strongly faded, or isabelline, in appearance. Isabellinism has been reported in several species of penguin. Isabelline and isabella are terms applied in Europe to very pale palomino or cremello horses, animals with a coat colour that is variously described as cream, pale gold or almost white; this is the primary usage of the French ("isabelle") and German ("Isabella") versions of the word. In horses, this colour is created by the action