Full Idea
If one takes a spectrum of colours from yellow to red, it might be that given a series of colour samples along that spectrum, each sample is indiscriminable by the naked eye from the next one, though samples at either end are blatantly different.
Gist of Idea
How can one discriminate yellow from red, but not the colours in between?
Source
Timothy Williamson (Interview with Baggini and Stangroom [2001], p.151)
Book Reference
Baggini,J/Stangroom,J: 'New British Philosophy' [Routledge 2002], p.151
A Reaction
This seems like a nice variant of the Sorites paradox (Idea 6008). One could demonstrate it with just three samples, where A and C seemed different from each other, but other comparisons didn't.
Related Idea
Idea 6008 Removing one grain doesn't destroy a heap, so a heap can't be destroyed [Eubulides, by Dancy,R]