The arrow is the only proof these were ever different

Two plain squares sit on an upper row. Left is flat crimson, right is flat teal — obviously, immediately different colours.

A hairline runs under them, with a short arrow dropping from each square to a second square directly below it.

Both lower squares are the same flat grey. Not a similar grey — the identical value, with nothing in either one to tell it from the other.

No text anywhere on the shirt. The two arrows are the only thing arguing this was ever a comparison, and not just four boxes stacked at random.

What happened between the top row and the bottom row?

Something converted both squares the same way, and the conversion couldn't tell them apart.

Colour has more than one dimension — hue, how saturated it is, and how light or dark it reads regardless of hue. A process that reads only the last of those sees crimson and teal exactly as it sees each other, provided the two land at a similar lightness. Two squares that look nothing alike in colour go in as different and come out sharing the one value they always had in common.

Why do two different colours turn into the same grey?

Because a red and a teal chosen at roughly matching brightness carry the same amount of light, even though they carry it in completely different wavelengths.

Convert either one to greyscale — print it in a single ink, fax it, scan it on a machine that only reads luminance — and the conversion keeps the light value and drops the rest. It isn't guessing wrong. It's answering a question that was never about hue in the first place, and the two squares happened to give it the same answer. That's a different failure from a print run that simply never laid down one ink at all, where the missing colour was never converted into anything — it just never arrived.

What is the arrow actually doing?

Carrying the one piece of information the shirt has left that these two greys used to be two colours.

Take the arrows away and the bottom row is just two identical squares — nothing to explain, nothing wrong with it. The arrows turn it into evidence: this one came from that one, and that one used to be readable at a glance as a different thing. The arrow doesn't restore the colour. It insists, permanently, that a difference existed here and is not visible any more.

What does it mean to inherit a copy where the difference is just gone?

It means holding a file that looks complete and isn't.

A faded photograph still tells you it's faded — the colour is thin, but it's there, and a careful process can sometimes pull it back toward what it was. This is a different failure. The information that separated crimson from teal wasn't weakened; it was never recorded past the conversion that made them the same grey. There's no direction to pull it back in. Whoever opens this file downstream sees two identical squares with no way to know, from the file alone, that they weren't always identical — the same quiet, one-way loss that shows up in a file re-saved past the point where it still remembers its own detail.

Is there anything to license in two squares of colour?

No. Flat crimson and flat teal belong to nobody, and the design doesn't reference a real palette, a brand's colourway, or a named chart.

A specific proprietary colour system — the kind a paint or print manufacturer names and numbers — is a different matter, and using one by name is where clearing it becomes part of the job. Two ordinary squares of red and teal, drawn for this design, need nothing cleared. Style has no owner. A work does.

Does this happen with any two colours, or just these?

Any two colours can collapse together if their lightness happens to match closely enough, which is why it's worth showing with an ordinary red and an ordinary teal rather than two shades that already look close.

A dark navy and a dark maroon do it. A pale yellow and a pale mint do it. What doesn't do it is a light colour paired with a dark one — the value gap is what a greyscale conversion actually reads, so a wide gap survives it and a narrow one doesn't, regardless of which two hues are involved. It's a narrower, more sudden version of what happens when a whole picture drifts toward one cast on its way somewhere — there, everything shifts together and stays distinguishable from itself; here, two things land on top of each other exactly.

Does it print well?

Yes — everything here is a flat square with a hard edge, close to the simplest shape a print can hold.

No gradients, no fine detail, no small type. Three inks cover it: the crimson, the teal, and one mid-grey for the lower row, plus a thin dark line for the arrows and the hairline. Keep the two colours close in lightness and far apart in hue — the same relationship the design is built on — and both read clearly against a pale oatmeal or stone ground.

How do I get one made?

Describe the two colours at JustOG — which pair, how the arrows sit, and how identical the lower row should read. Pick a direction, drag the crop frame, see it composited on the real garment, and it's made to order and shipped.

Designs other people have published are in the shop.

Whoever gets the file next sees two grey squares joined by an arrow that used to mean something they can't get back.