Kaweco Paradise Blue is a pretty good match for my TWSBI Diamond 580 in Christmas Green. The pen body is a little more green than the ink color but not too bad a match.
Kaweco Paradise Blue ($17.50 for a 30ml bottle) is a turquoise ink that leans a bit more green than most turquoise inks. It’s my second favorite Kaweco ink after Summer Purple because the hue is so unusual for a company that only makes a handful of colors. The label color is a little misleading as it shows a more bluish color.
Paradise Blue dries quickly and is not as watery as the closest color match I could find, De Atramentis Petrol which would make Paradise Blue a better option for wider nibbed pens.
In my hunt for comparison inks, I didn’t find too many colors that were similar. In terms of darkness, Paradise Blue fell between two offerings from De Atramentis: Petrol, which is a little bit darker and Mint Turquoise, which is a little lighter color overall. Most inks that aspire for a turquoise hue are much bluer. Paradise Blue walks that fine line between the slightly greenier hues that I found as a comparison and the much bluer turquoise inks like Lamy Turquoise or Sheaffer Skrip Turquoise.
Overall, Kaweco Paradise Blue is a good, solid ink in a pleasing color at a reasonable price.