Anyhow, Oak green, was a rare option on the mk2's, it was an understated colour, and indeed made the golfs look cool and classy, it does have a slight reference to racing green (they share some of the same paint colours), but nothing more.
Oak Green is sought after because it was the colour no one really wanted.
It first appeared on 88 Campaigns where the colour options were met blue, graphite grey (nearly black), and oak green. the graphite was the most popular colour, the blue next, and the one people didn't want was the oak green.
It then appeared as an option after the Campaigns had run their course. I have a feeling it was only available on 16vs but I'm welcome to be proven wrong. I know by the end of the Mk2 run in 1992 you could get also sorts of combinations.
When it became an option after the Campaigns - it still wasn't a popular colour.
The problem is that as Golfs have got older and more and more scrapped, certain colours have become rarer, and thats why they are so popular now. Pure and simple rarity value.
The irony is that Oak Green is no longer the rare colour. The rare colour is becoming graphite which suffer from looking absolutely rubbish when they get older and so get disguarded more. An even more rare colour is the metalic greeny blue that was on the very early 16vs.