Here are the cartridges for the Coleto. These are the .4mm size, and I had Brad select the colors due to my being so indecisive. Brad chose Violet, Apricot Orange, and Blue-Black. I called the Apricot Orange "Tangerine Orange" in the written sample, but it is, indeed, Apricot Orange.
I may not speak Japanese, but there is a spiffy little diagram on the back showing one how to load the barrel with the cartridges. The cartridges are very easy to install, but it is nice that a picture is included in the event there is any confusion on setting up your new Coleto.
To load the cartridges, you lift up the white cap on the top of the pen, slide the cartridges in, and close the cap over the top.
Now the pen is all set to go. I do wish the clip was a bit more substantial, but at $2.50 it is pretty hard to complain. The barrel is otherwise the perfect size, and I think the 5-color barrel might be better still, especially if you have larger hands or prefer a thicker barrel. The color of the barrel is described as 'black', but it is really more of a translucent smoky grey, and I dig it.
This style of grip is one of my favorites. The material alternates between hard plastic and soft rubber, so it is not too squishy or too firm. A similar style of barrel is used on the Uniball Signo Bit and the Bic Atlantis.
And now we are ready. This image makes it look like a menacing torpedo of multi-pen action.
(Click the image above for a larger picture of the written sample)
I did make note that I thought the Apricot Orange was scratchier than the other two colors, but I am going to chalk this up to one bad refill. If I get another Apricot Orange and it is scratchy, I will probably avoid that specific color going forward.
The writing sample doesn't accurately portray the colors, so I added this image for better accuracy. Again, Tangerine Orange is incorrect; the color is Apricot Orange.
The ink is even more vibrant in person, and Jet Pens offers refills in tons of different colors. At $2.20/cartridge, this pen ends up being a little bit pricier than the ballpoint multi-pens, but you are not going to get the color selection or colors that are quite as bold and vibrant. I love this pen and, if you haven't tried it, I suggest you make haste in trying it out soon.