All of them: it was great.
So, Book III (aka The World of Nemesis) ran from 335-349 and took over the centre of the comic, and so the colour pages. Many of the episodes were only four pages long (10 of 15), so of the 67 pages, 30 were in colour. That's about 45%.
Book VI (Torquemurder) also nabbed the centre for the first half (episodes 1-6): so that's progs 482-487.