I'm not really colour-blind at all. I only said that to fool Bluebottle.
You know how iTunes sometimes auto-downloads album art for your albums (even without you necessarily asking for it)? And how sometimes, it gets it...a bit wrong? Like the US release instead of the UK release (or vice versa), a reissue instead of the original, the album instead of the 7" single that you've just ripped from vinyl (e.g. Madonna's True Blue, George Michael's Faith)..?
And sometimes, it's only slightly wrong, but to a pedant (possibly borderline OCD person) like me, irritatingly so...
For example, this (the auto-download version):
...is obviously a very different shade of blue to this (my scanned cover art):
And if anyone even dares to say I'm wrong, I shall set an optometrist onto them...