ai guidelines & prompts

Rare Colors — AI Guidelines & Prompts Case Study
Case Study AI Guidelines & Prompts / Rare Colors
Client — Rare Colors

THE BRAND
SPEAKS
even without you.

AI is only as good as the instructions it gets. I created a unified AI copy prompt for Rare Colors — highly specific, highly repeatable guidelines that let anyone on the team generate on-brand copy through AI, even when a dedicated copywriter wasn’t in the room. The result: consistent voice across every channel, at speed, without sacrificing quality.

Role
AI Copy Strategist
Scope
AI Prompts & Guidelines
Client
Rare Colors
Editorial visual
Editorial visual
01 — The Challenge

AI WITHOUT
GUARDRAILS

Rare Colors’ team was already using AI tools to draft copy — but everyone was prompting differently. One person got generic luxury filler. Another got something too casual. The output was inconsistent, and the brand voice I’d built was getting diluted every time someone opened ChatGPT without a framework. The tool wasn’t the problem. The instructions were.

02 — The Approach

ONE PROMPT.
ONE VOICE.

I developed the Rare Colors Unified Copy Prompt — a single, detailed system instruction that any team member could paste into their AI tool of choice. It encodes the brand persona, core voice principles, specific do/don’t guardrails, and the exact language patterns that make Rare Colors sound like Rare Colors. Specific over vague. Sensory over generic. Expert, not arrogant. Never “Shop Now!”

The Rare Colors Unified Copy Prompt document
The Document
THE UNIFIED
COPY PROMPT

A copy-paste system instruction built to slot directly into any AI tool. It includes the brand persona (“an expert friend at a private viewing”), the three-word voice framework (Rare. Personal. Inevitable.), specific language rules (“never use ‘beautiful jewelry’ — use sensory, specific details like ‘a 2.8ct Fancy Vivid Yellow pear the color of afternoon light through a glass of Sauternes’”), and a strict list of what the voice is not: not hype-driven, not generic luxury filler, not overly technical, not casual or Gen-Z ironic, and never apologetic or discount-coded.

UNIFIED COPY ACROSS CHANNELS —
EVEN WITHOUT A COPYWRITER PRESENT
The prompt gave every team member — from the brand director to the social intern — the ability to generate on-brand copy at speed. No more inconsistent tone between channels. No more “exquisite, stunning, gorgeous” filler. The brand voice held, whether the output was an email subject line, a social caption, or a product description.
01
Voice Encoding
Translated the brand voice framework into AI-readable system instructions — converting tone pillars, guardrails, and copy patterns into repeatable prompt architecture.
02
Guardrail Design
Built strict do/don’t rules into the prompt: what words to avoid, what patterns signal AI slop, and exactly how the brand sounds vs. how it doesn’t.
03
Team Distribution
Packaged the unified prompt for internal sharing — designed to be copy-pasted by any team member into any AI tool with zero onboarding required.
03 — The Framework

PROMPT ENGINEERING
FOR BRAND

This wasn’t a vague “write in a luxury tone” instruction. The prompt encodes specific sensory language patterns (“the soft blush of a pink diamond” over “beautiful jewelry”), positioning rules (the customer is discerning and bold, never basic), and explicit anti-patterns: no em-dashes used as AI crutches, no “It’s not…It’s…” constructions, no “In today’s world of diamonds…” filler. Every line of the prompt was battle-tested against real copy scenarios.

04 — The Impact

SPEED WITHOUT
SACRIFICE

The unified prompt solved a real operational problem: how does a growing brand maintain voice consistency when not every piece of copy goes through a dedicated copywriter? The answer isn’t to ban AI — it’s to make AI speak the brand’s language. Now Rare Colors gets on-brand output at the speed of a prompt, across social, email, ads, and product copy — and the voice holds.

KEY
DELIVERABLES
What shipped.
i
Unified AI Copy Prompt
A single system instruction encoding Rare Colors’ brand persona, voice pillars, language rules, and anti-patterns — designed for copy-paste use in any AI tool.
ii
Voice Guardrails & Anti-Patterns
Strict rules for what the brand voice is and isn’t — specific words to avoid, AI-generated patterns to flag, and tone boundaries that keep output on-brand.
iii
Internal Distribution Framework
Packaged for team-wide adoption — shareable, zero-onboarding prompt documentation that any staff member can use to generate on-brand copy independently.
Rare Colors × AI Guidelines & Prompts Portfolio