Pilot ILMILY Color Two Color Review: The Magic Color-Changing Pen

I picked up my first ILMILY Color Two Color pen at last year's Bungujoshi Expo, where it won an Excellence Award. At first glance, it looked like another FriXion pen with its white barrel and friction eraser nub on the end. Then a demonstrator rubbed a line of navy ink and it turned sky blue right in front of me. Not erased. Changed. That's when I understood what Pilot was trying to do here.

The secret is thermosensitive ink similar to what Pilot uses in their FriXion gel pens, and the color changes with any heat source. The friction eraser on the pen cap generates enough heat through rubbing to trigger the transformation. This is the same basic technology as FriXion, but engineered differently. FriXion ink turns completely clear at around 60°C. The ILMILY Color Two Color ink shifts to its secondary color at a similar temperature and doesn't disappear.

Here's what that means practically: if you leave your notebook in a hot car in summer, your navy writing will turn light blue. If you spill hot coffee on your notes, those cherry marks become peachy. The color change is permanent unless you cool the ink below -10°C to -20°C, which reverses it back to the original shade. I tested this by putting a marked page in my freezer overnight and the colors did revert, though I can't imagine doing this regularly.

The 0.4mm tip on the gel pen writes finer than the FriXion Ball Knock (which uses 0.5mm or 0.7mm tips) and noticeably finer than the Uni-ball Signo erasable line. For comparison, it's about the same width as a Muji gel pen at 0.38mm, making it suitable for detailed note-taking in tight spaces like planner boxes or margin annotations.

I've been using the Navy to Gray pen as my primary task list pen since December. My system is simple: write tasks in navy, rub completed ones to turn them gray. It works better than I expected for two reasons. First, the color change is immediate and complete. One or two passes with the eraser cap and navy becomes a consistent light blue-gray. Second, unlike fully erasing with a FriXion (which can leave ghosting or paper damage if you rub too hard), this method keeps the text readable while clearly marking it as done.

The Cherry to Peach combination surprised me. I thought it would be too cute for professional use, but the cherry shade writes as a muted red-pink that looks presentable in work documents. When rubbed to peach, it becomes a soft salmon color perfect for secondary highlighting. I use this for editing draft articles, marking first-pass edits in cherry and approved changes in peach.

The ink flow is smooth and consistent. It writes more like the FriXion Ball Knock than the original FriXion Ball, with less feedback and a wetter line. This is good for quick writing but means slightly longer dry times. On Midori MD paper, it dries in about 3-4 seconds. On cheaper copy paper, maybe 2 seconds. It doesn't bleed through either paper type, though there's slight ghosting on thin notebook paper.

The ILMILY pens use ink similar to the Pilot FriXion Waai pens, which are the muted pastel version of the FriXion line. The Waai inks are softer and lighter than standard FriXion colors, and the ILMILY Color Two Color inks follow that same aesthetic. Your starting colors are already somewhat muted, which means the secondary colors are quite pale.

If you're used to the bold saturation of something like Pilot Juice pens or even standard FriXion, the ILMILY colors will feel understated. The Black to Gray writes more like a dark charcoal than a true black, and when rubbed, becomes a medium gray rather than a light gray. This isn't a criticism, just something to know. The whole series prioritizes subtlety and coordination over high contrast.

For actual writing feel, these are smoother than the Uni-ball R:E erasable pens, which have a plasticky, almost waxy feel. The ILMILY pens are closest in performance to the FriXion Ball Knock series but with that finer 0.4mm tip.

The Color Two Color markers work on the same principle but in a highlighter format. They change colors when you rub the page with the friction eraser on the end of the barrel, perfect for highlighting text and then marking which highlighted sections you've addressed or reviewed.

I tested the marker version on textbook pages and research papers. On standard 80gsm printer paper, there's minimal bleed-through, though you can see a faint shadow on the reverse side. The color change requires a bit more rubbing than the gel pen because you're working with a thicker ink layer, but it still happens cleanly within 3-4 passes.

The Color Two Color series is actually the third series from Pilot ILMILY, and it includes planner essentials like highlighters, gel pens, planner templates, and stamps. This suggests Pilot is building a complete planning ecosystem around the color-change concept, though I haven't tested the stamps or templates yet.

After three months of daily use, I think the ILMILY Color Two Color line works best for people who:

- Use physical planners or bullet journals with daily task tracking
- Want a gentler visual hierarchy than stark crossed-out items
- Appreciate Japanese stationery aesthetics (muted colors, understated design)
- Don't need their writing to survive extreme temperatures
- Already enjoy FriXion pens and want something with a twist

It's less ideal for students who need archival-quality notes, office workers in very formal environments where even subtle pink tones might be too casual, or anyone who needs vivid, high-contrast colors.

For me, working in Shibuya and managing Fujinote's inventory tracking, the Navy to Gray pen has become genuinely useful. It sits in my shirt pocket daily. I reach for it more than my black Jetstream or even my reliable Uni Signo 0.38mm. The color change adds just enough functionality to make it more than a novelty, which is rare for pens with special features.

The Cherry to Peach marker lives on my desk for article editing, and I've ordered the Emerald to Mint gel pen to test for a different notebook. That tells you what I think about whether these are worth carrying long-term. They're not perfect, but they solve a specific problem in a clever way that actually works in daily practice.