Aqua Blue
Aqua Blue is very similar to Turquoise but with a little more blue tones.
I have found this colour looks good in some business and all personal notes.
There is a brightness about this blue and when I look a entire page of notes with this colour, you have to like a bright bue to like the look.
The performance is fairly standard with the Diamine line, reasonable drying time, and depending on the pressure with which you write, the ink was dry within five seconds. I only found some smearing within a five second time frame where I had made heavy strokes and at the end of the stroke, where the pen rested on the paper there was additional ink on the paper. There is overall good colour tones.
The colour swatch on the Diamine website is a good representation of the colour of ink.
Asa Blue 
I loaded my pen with the rich Asa Blue ink, and as soon as the first letters were being formed on the paper I knew this one was going to very popular. I am really enjoying using this colour.
Rich blue, some see teal in it, however, it is a good bright blue in my books.
Performance has been very good. I have tried it in various pens and the flow is good, the drying time very reasonable.
There is no significant shadding. I saw that as I have used it with pens fitted with both Stub and Italic nibs so there would have been lots of opportunity for shadding to take place. The sample that I have added to this page is written with a Broad nib in the Montegrappa Espressione pen. That is a big nib, and it places a fair amount of ink on the paper. Good performance.
The colour sample on the Diamine website is a good representation of the colour of this ink.
All I can say is get yourself a bottle of this ink and enjoy!
Blue Black
I really enjoy this colour, but I lean towards darker richer colours in fountain pen ink.
My experience with the pen is relatively good overall performance from this ink in a variety of different pens. I have received notes from individuals who found it did not have a good flow in a range of pens.
I found that business writing looks very strong and easy to read because of the depth of colour. This ink is just made for a great business letter signature! It is dark and photocopies very clearly - always a good consideration for letters etc that you are signing at work.
The deep blue-black colour has an interesting undertone of grey-blue and this gives the ink a very interesting tone or shading.
Color swatch from the Diamine web site.
China Blue
The colour swatch on the Diamine web site shows this colour of ink to be a very light blue.
But, when when I loaded up one of my pens with this ink, it had far more punch than the colour swatch and I enjoyed using the ink.
I liked the crisp blue look and the ink has enough colour saturation for my liking. Now over time, this is one of the inks that I come back to.
Colour swatch from Diamine Web Site shows the ink as being a pastel-like blue.
Florida Blue
is what I would call a good middle range blue. It is not one that I have used a lot as I tend to lean towards bolder more saturated colours.
Colour swatch from Diamine Web Site:
Havasau Turquoise
This is a very appealing colour, a rich blue with some green to go it a turquoise tone. The blue in this gives it a richer colour than the Turquoise colour that Diamine produces. There is a distinctive look to this ink. The color swatch on this Diamine site is not a good representation of this ink.
I like the colour of this ink, but must put out a note about staining. This colour has left ink stains on the outer body of one of my celluloid pens so I have stopped using it in that type of pen.
I was surprised at how quickly the ink stained the celluloid. Ink, after a fill-up, flowed from the nib to the inner cap section. When I posted the cap section on the body of the pen, after an hour or so there was an ink stain on the end of the pen. This was not after an extended period of use. Staining on the spot!
The colour is good and I am limiting its use to my all metal or my darked-colour resin pens.
Colour swatch from Diamine Web Site has much more blue than the ink holds.
Imperial Blue
If you looked at the colour swatch from Diamine web site you would think of this as a blue ink.
When you look at the ink, and write with it, it has a very definite purple/violet colour tone.
But, despite the variance between the colour of the ink and the web site colour swatch, it is a very bold, bright, solid ink. When I go back and look at notes I took at meetings it the colour looks fine.
I have been using this ink quite a bit and sometimes it seem s to come across like a true blue,other times the purple or violet tone is very evident.
Colour swatch from Diamine Web Site.
Indigo Blue
has a flat colour appearance, however, fairly good colour density.
Even from the scans, there is less punch to this ink than some of the other blues available from Diamine.
I would almost describe Indigo Blue as a light blue-black colour of ink because of the light black tones throughout.
Colour swatch from Diamine Web Site:
Majestic Blue
I call this a blue-black ink because of the very dark tone of the ink. It has quickly become one of my most used inks in the pens that I find it has good performance..
The ink takes a reasonable time to dry. I use a variety of nibs, most being broad or stub, and within five seconds the ink is dry. Some times if the nib is large it can take up to 10 seconds. From what I see in many reviews, up to 10 seconds is considered reasonable.
This ink is wetter than some of the other colours, that means great flow, but a fair amount of ink hits the paper.
I have had issues with this ink in terms of its performance in Montegrappa and OMAS pens. Other pen users have written sharing similar experiences. The ink seems to dry in the feed, and it always takes a stroke or two to get the pen flowing.
This is the colour that would replace by Parker Penman Sapphire Blue!
Colour swatch from Diamine Web Site:
Mediterranean Blue
This is an interesting colour, a light, soft tone but with a bit of character.
It looks very good on personal notes or cards.
Good performance, nothing to stand out from the other colours in the Diamine line.
Colour swatch from Diamine Web Site:
Marine Blue
This is part of the turquoise group of blue inks. It is a little lighter in tone that the Havasu Turquoise but the ink has what I call an "easy on the eye" look to it. I have used it in both business and personal note purposes.
The colour swatch on the Diamine web site is fairly representative of the colour of ink in use.
Midnight
This is another colour that I have really taken to. It came out in 2009 and it is one of the most used colours in my collection. A very dark, rich blue, black. Leaves a great dark solid line of ink on the page. Not a lot of shading, despite the width of the nib that is being used. Midnight Blue - Diamine InkColour swatch from Diamine Web Site.
Presidential Blue
Presidential Blue has a darker tone than say Royal Blue or Washable blue, and a nice solid look to it.
Darker tones than say, Florida or Royal Blue. Because of the toner, this ink, from my preference, stands on the paper better. I look at a page of notes and they look good and strong. The colour is not as dark as the web HTML colour for Presidential Blue, but overall the ink has a good look.
Prussian Blue
is close to a lighter blue-black colour. When I gave this ink a full day's test at the office I concluded it was really a grey ink. In fact one day I held asked for feedback from a co-worker and it was a resounding: grey not blue black.
When I have scanned ink samples there are hints of blue that come on on the scan, but not so in actual writing. I think this is more of a personal stationary ink. In the office, I noticed that because of the grey tone, for letters I signed with this ink, the signature did not photocopy very well.
The ink has good performance, it dries very quickly, a little quicker than some of the other colours.
Despite the various pens I have used, the ink just never looks as dark as the colour swatch on the Diamine web site. I have written with a Pelikan M1000 with a Broad Nib, now that is a pen that really drops a fair amount of ink on the page. Still, no where near the color swatch.
Royal Blue
This is an easy-on-the-eye blue with good colour although a very light blue.
Looks great on a card for a short note but I have found that where I have written pages of meeting notes with this ink the enough not enough depth of colour. The page looks washed out.
II would lean towards a darker, stronger colour.
Sapphire Blue
Sapphire Blue - (New Century Line) this is a good colour if you like bold colours as the ink stands out on the page.
As the ink dries on the paper a bit more of the blue tone comes out, but when you start to write with it, purple is the colour that hits you.
The ink does has some feathering properties. I have noticed when using it (Pelikan M1000, Broad nib) there was some feathering of the line of the characters. When I changed ink in the same pen on the same paper the feathering did not take place.
Sargasso Sea
When I saw a sample of this ink, it looked like a rich blue, and I immediately ordered a bottle. When I started to write with the ink I found it was much more than just a rich blue, this is a very bold intense blue.
I have used it for a few days and my first experience was not that good as I found the quality of flow etc varied by paper. At the office, with the cheaper copier paper the ink was sluggish. I was also using a Delta Dolcevita Oro with a large stub nib, and the pen would dry if I left with the cap off.
But over the next few days, as I wrote in different papers the ink was actually better. So I am continuing to use it. It dried in about 5 seconds, so that part is okay.
The only ongoing issue with this ink is that it does dry in the pen, so if you come back to a pen you have not used in a day or so, you have to flush a bit of ink to get it going again. That is a bit of a pain.
Steel Blue
was one of the initial colours I ordered from Diamine.
The colour is not what was expected in terms of a steel blue. It is more of a green with a blue under tone. The colour, however, has certainly grown on me and I have enjoyed using it at work and for personal notes.
My experience with this ink is a bit more green comes across than the colour sample on Diamine's web site.
Turquoise
is slightly darker than the Aqua Blue ink.
Overall, good tone, and enough depth of colour that it will "hold a message" as soon brands have a turquoise that seems to fade away.
I have really enjoyed this ink and it will be one of the colours for my next order from Diamine.
The ink does not look like the colour swatch on the
Twilight
I have always liked blue-black ink. This ink I have enjoyed using. I always like richness in the tone. This is good in that aspect. As the ink dries, there is a bit of a blue-grey look that is left on the page. Easy on the eye.
In terms of peformance, this ink has been performing very well in various pens that I have.
I am using this ink so much, I show how the ink is in terms of time to dry. On the left I ran my finger across the writing after 5 seconds, and on the right, I wrote again, and then ran my finger over the writing after 10 seconds. So between a 5 to 10 second dry time on the paper. That's good.
The colour sample on the Diamine web site is fairly good, but it shows more blue than I have experience in using the ink.
Interestingly, I also use the Blue Black by Diamine, and these two colours are very close. I show the colour sample from the Diamine website to the right .
I look at the Blue Black and it is darker in tone. My wife, who is an artist, says the Twilight has a green/grey undertone to the colour and finds the Blue Black a darker and more true Blue Black.
So there you go, lots of comparison on this colour.
I am using it, and enjoying the ink.
Washable Blue
This ink has a flat soft look. It is easy on the eye, although for my preference, I prefer a blue with a little more punch.
For many this could be a good mid-tone blue.
I not sure what the Washable really stands for. All the Diamine inks are water based so none or water resistant. Some, I have noticed from getting ink on my fingers need a bit more of a scrub to get off.
WES Kensington Blue
Diamine made this ink for London's Writing Equipment Society (WES).
This is an interesting blue, although you do no see the tone on the colour swatch on the Diamine web site, when you write with the ink, there is a turquoise tone.
The ink performs well, although in terms of drying, this colour I found dries quicket than some of the other colours.
The colour swatch on the Duimine site is not a good representation of the colour of the ink.