In answer to a couple of your questions I have put this comment from the e-mail I received from Phil at Diamine earlier today.Have a look at all the sites with Diamine swabs or swatches etc and see if you can find any similarities. I can't.
The colours will be unique to the set and will not be sold separately, this product is not a Limited addition item.
Thank you so much for taking your time and answering me!
I have just now discovered your thread and read through it. It's really an interesting set, but I wonder why they matched those colors with those composers