4AD have released a deluxe 4-CD box set which contains almost every commercially available bit of music by Colourbox, and also includes a rare BBC session which I don't think was ever officially released (I had a bootleg of some of it).
It's beautifully packaged, including heavy stock cards with the cover art and credits for every one of the original releases.
Sound quality is excellent - there is no loudness war peak limiting at all. In fact, it's rather quiet compared to most modern releases. You'll want to crank your volume up. In the few A/B comparisons I made with the original 80's releases, the new ones are all brighter and clearer with better defined bass.
At US$30 for 4 packed CD's it's a steal. Get it!