The color purple does not exist outside your brain.
I know. Stay with me.
Every color in the rainbow — red, orange, yellow, green, blue, violet — has its own wavelength of light. Its own address on the spectrum.
When your brain combines signals from multiple cone types in your eye, it can land on a color that DOES exist on the spectrum:
• Red and green mix into yellow — and yellow has its own real wavelength (~580 nm) on the spectrum
• Blue and green mix into cyan — also a real wavelength (~490 nm)
The brain’s “guess” matches something that actually exists in the physical the physical world; in the rainbow.
What Makes Purple Different
The visible light spectrum runs in a one direction:
red → orange → yellow → green → blue → violet.
It’s a straight line.
But when red and violet signals, which sit at the two opposite ends of that line hit your eye at the same time, the brain again tries to average them and find the middle. The only middle average in the physical world is green. The wrong answer.
There is no middle ground between the two ends of that straight line that makes sense.
So what does the brain do?
The brain does something remarkable: it bends the line into a circle, connects the two ends, and invents a color to fill the gap.
That invented color is purple.
It has no wavelength.
You cannot find it in a rainbow.
It has no existence outside your skull.
Color scientists call it, a “non-spectral color” — a color that exists only as a neural output.
It is not an illusion. It is a consistent, reproducible neural construction — a solution the brain generates when the real world offers it no clean answer.
You see it with complete confidence. You'd bet money on it.
But it has no counterpart in the light that caused it.
The nervous system prefers a confident invention over an admitted gap.
The Heresy: Your team's doing the same thing
Your team has a picture of the customer. It is vivid, detailed, and shared. Everyone in the room sees the same thing.
Some of it is real. Years of sales calls. Renewal patterns. Service complaints. Buying behavior.
Combined, those signals have a wavelength you can trust.
But what if some of it is purple?
I’ve watched executive teams bet millions on customers they hadn’t actually validated in years.
Not because they were stupid.
But because the model felt real.
Sales had anecdotes. Marketing had personas. Product had usage data. Finance had a forecast.
Everyone had fragments.
Nobody had the customer.
Then the market moved. The customer changed. But the team kept worshiping a customer that no longer existed.
Then sales growth no longer existed
A sales org doesn't fail because it stops trying — it fails because it keeps trying, precisely, at the wrong target.
Every quarter, the team optimizes messaging, pricing, and outreach against the customer model in the room. If that model is purple — invented consensus standing in for validated fact — every optimization tightens the aim on a target that isn't there anymore.
The pipeline doesn't just underperform. It performs exactly as designed, against a customer who moved on two years ago.
That's the part that should unsettle you: this isn't a sales-execution failure.
Execution was fine. The target was fiction. When old assumptions don't mix cleanly with new market conditions, or a new segment doesn't mix well with the one you know, the team's "brain" sees a gap.
It fills the gap and hands your team a vivid, confident, fully-formed picture of the customer — with nothing outside your brain to show for it.
Now you have purple.
And here's where CEOs push back on me.
But Don — we talk to customers. We have data. We have feedback loops. We have sales calls.
Receiving information is not the same as validating a model.
The brain receives light too. It still invents purple!
The danger is not that your team has a customer model. The danger is that the invented parts feel identical to the real parts. Yellow and purple feel equally solid inside the mind.
Confidence does not distinguish between them. That settled, everyone-agrees feeling isn't evidence your answer matched reality — it's evidence your brain successfully resolved a conflict. Those are not the same thing.
Organizations build entire strategies on invented assumptions — not because they were careless, but because the brain is very, very good at making invented things feel real. The color was right there. Everyone could see it. No one thought to ask whether it had a wavelength.
Confidence in your customer model is a neurological event.
Not a validation result.
Monday morning actions
Pull one core assumption your team holds about what the customer wants right now — not two years ago. Ask whether it's yellow, grounded in direct customer behavior you can point to, or purple, something the team invented because the real signals didn't add up cleanly.
Test it against the newest data you have, not the data that built the original model. If your most recent customer behavior doesn't match the model the team is still selling against, you've found your first false wavelength — and it's worth investigating before you spend another quarter optimizing against it.
Bring the finding to the room that owns the number, not the room that owns the story. Sales and marketing built the model together; they're the least likely to see where it went purple. Finance or product, further from the narrative, often spot it faster.
If the answer is uncomfortable, good. It's worth more than the strategy you built on top of it.
It's worth more than the strategy you built on top of it.
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