The design kit — brand bible and design tokens as structured data — step 3 of 10

Banned looks are half the brand

Ask a client what their brand looks like and you'll get twenty minutes of adjectives. Ask what it must never look like and you'll get the useful answer in ninety seconds: "Nothing that looks like our competitor. No gradients — we did that rebrand, we're out. No stock-photo people grinning at salads."

Working designers know the "never" list is load-bearing. It's why the bible has that page near the back, and it's the page image models violate first — because models are trained on the average of the internet, and the average of the internet is gradients, neon glow, and stock-photo smiles. Left unprompted, the model regresses to exactly the looks your client pays you to avoid.

So in the kit, banned is not an appendix. It's a first-class field with three kinds of entries:

• Model clichés — the default AI look: gradients, lens flare, purple-teal glow, plastic skin, watermark ghosts. These go in every kit you ever build.
• Brand scars — looks this client has specifically retired or been burned by. The old rebrand's gradient. The mascot style from the agency they fired.
• Competitor territory — visual language the market already associates with someone else. If the competitor owns dot-matrix orange, your kit bans dot-matrix orange.

The compile rule that makes it real: everything in banned becomes the negative section of every prompt, automatically. --no gradients, neon, stock-photo smiles on Midjourney; "Do not include…" prose on Flux. You never re-type it, so you never forget it on asset #37. One field, zero recurring vigilance.

What makes a kit valid

Because the kit feeds everything downstream, a broken kit poisons every asset in the batch. Before a kit is allowed to compile, it has to pass inspection:

1. All five fields present — brand, palette, type, motifs, banned. A kit without type means the model freelances the lettering.
2. banned is never empty. An empty banned list doesn't mean "this brand allows everything" — it means nobody had the ninety-second conversation. Reject it and go have the conversation.
3. Every hex actually parses, and text colors clear contrast on the background. That last one is a legal floor, not a taste call — it's the next drill.

Validation runs before compilation, always. The checkpoint at the end of this lesson enforces exactly that order.