Full Idea
It is not always possible for nominalists to translate all statements putatively about universals as statements about particulars. It is not possible for 'red is a colour' and 'red resembles pink more than blue'
Gist of Idea
Nominalists cannot translate 'red resembles pink more than blue' into particulars
Source
Frank Jackson (Statements about Universals [1977], p.89)
Book Reference
'Properties', ed/tr. Mellor,D.H. /Oliver,A [OUP 1997], p.89
A Reaction
His second example strikes me as the biggest challenge facing nominalism. I wish they wouldn't use secondary qualities as examples. I am unconvinced that the existence of universals will improve the explanation. It's a mystery.