I would like to know the minimum number k such that the plane R^2 can be coloured with k colors such that no colour contain all the possible distances. In other words, a colouring such that each color forbids a distance (not necessarily the same as it is the case for http://en.wikipedia.org/wiki/Hadwiger%E2%80%93Nelson_problem)
Has this problem been studied? It is easy to prove that 2 colors isn't enough, but I don't know for 3 colors... We also know that this number k is at most 7 (using http://en.wikipedia.org/wiki/File:Hadwiger-Nelson.svg for example), but I did not find any better bound yet.
Bests,