Customers & Automation
Colour Formula Library
Last updated 19 May 2026
Colour Formula Library
Record colour formulas per client visit — bases, developer, technique, processing time, notes. Immutable per-visit history so corrections later have a clean audit trail. PRO; primarily a chair-side mobile feature for hair venues.
Where to find it — Mobile: Booking detail (Chair View) → Record formula or Use last formula. Web: Customer profile → Formulas tab; also a summary chip on the booking-detail sheet.
TL;DR
- Record per-visit formulas with bases, developer, technique, time, notes.
- Immutable history — formula details lock on save; notes editable with full audit trail.
- Auto-attaches to the booking; auto-summarised on the customer's "must-know" strip.
- Use last formula prefills from the most recent — copies, never overwrites.
- Link formulas to treatment photos for matched visual + recipe history.
- PRO.
What goes in a formula
| Field | What | Constraint |
|---|---|---|
| Bases | The colour mixture | 1 to 8 rows. Each row: shade, parts, brand |
| Developer | Hydrogen peroxide developer | volume (10 / 20 / 30 / 40 / Other) + brand |
| Technique | Application method | roots only / global / balayage / foils / bleach wash / toner / free (custom text required when free) |
| Processing time | Minutes the colour develops | Integer minutes |
| Notes | Anything else — feedback, sectioning, observations | Free text |
Linked context (auto-populated):
- Customer (required, derived from the booking)
- Staff member (derived from the user who saved)
- Service (derived from the booking's primary service)
- Booking (the booking you saved from — optional if recording outside a booking context)
Recording a formula
From Chair View (mobile)
- Open the booking on mobile.
- Chair View renders (when the booking is in service or 15 min before).
- Tap Record formula (or Use last formula to start from the customer's most recent recipe).
- Fill bases, developer, technique, time, notes.
- Save.
The formula attaches to the booking and the customer's main colour_formula cache updates so the next visit's "must-know" strip shows the summary.
From the customer profile (web)
Web shows the formula history under the Formulas tab. You can record manually (without a booking context) here, useful for catching up on a visit you didn't record at the time.
Use last formula
The Use last formula action prefills the form with the customer's most recent recipe via ?preFill=1. Three reasons:
- Repeat visits where the formula is the same — quick save.
- Slight variations (different developer volume, extra toner) — edit the prefilled form.
- Reference what they had last time without retyping the whole thing.
Always saves as a new row — never overwrites the previous formula. The audit trail stays clean.
Immutability
The formula itself (bases, developer, technique, time) is immutable once saved. To "change" a formula, save a new copy.
Reasoning: a colour correction six months later needs to see exactly what was applied last time, not whatever the stylist might have edited to retroactively. The immutable record protects against accidental rewrites and creates a clean audit trail.
Exceptions:
- Notes are editable — corrections to observations are common. Edits are tracked in
notesHistory(append-only jsonb log). - Soft-delete and restore — if you saved by mistake, soft-delete recovers without breaking the audit (the row stays in the DB, just hidden).
Notes history (owner-only)
Notes can be edited freely, but the system keeps an append-only history of every change. Owners can view it from the formula detail (via the getNotesHistory endpoint surfaced in the web Formulas tab).
Useful for understanding why a stylist updated their observation between visits or to settle a "what did we say last time" discussion.
Linking to treatment photos
From any treatment photo on the customer's timeline, tap Link to formula to attach the photo to a specific formula. Constraint: same-customer guarantee (you can't accidentally link a photo of Sarah to a formula on Tom's record).
This builds a visual+recipe history together — the "before/after" photos beside the formula that produced them. Especially useful for clients with colour journeys (lift, fade-out, toner refresh).
See Treatment Photos for the photo timeline itself.
The customer "must-know" strip
Each customer row in the clients list and on the booking detail surfaces a must-know strip showing the latest formula summary — bases + developer + technique compressed to one line. Powered by the deterministic buildColourFormulaSummary helper; cached on venue_customers.colour_formula so it renders cheap.
Example: "6N + 7AA (1:1), 20vol Schwarzkopf, roots only · 30min"
Recent shades autocomplete
When you're entering a new formula, the shade field autocompletes from the venue's recent formula shades — privacy-stripped (no customer attribution). Speeds up data entry for venues that consistently use the same palette.
Last formula card
On the Chair View and the customer profile, a Last formula card surfaces the latest summary with three actions:
- Use last formula — prefill new formula
- View history — open the full formula list for this customer
- Record — fresh formula from scratch
How long ago was the last formula?
The countSinceFormula query powers a "N visits ago" badge on the must-know strip. Matches by email/phone on bookings since the latest formula's createdAt. Useful for "last colour was 8 visits ago — they're due".
Mobile parity
Chair View on mobile is the primary chair-side surface. Web shows the Formulas tab on the customer profile with the full history and editing surface. Both share the same router and schema.
Tier
PRO. FREE venues:
- See the formula chip on customer profiles as a locked teaser
- Read-only — no recording or editing
- The Use last formula and Record actions show an upgrade prompt
What's NOT in scope today
- No AI assistance — formula generation is operator-entered, not AI-suggested. The summary string is deterministic.
- No batch import — formulas are recorded per-visit.
- No print/export — view in-app or via the data export ZIP under (future inclusion).
- No formula sharing across venues — formulas are venue-scoped (a customer with bookings at two venues has separate formula histories).
Common mistakes
| Problem | What to check |
|---|---|
| Can't edit a formula I just saved | Formula details are immutable. Save a new formula with the correct details — the old one stays in history. |
| Notes edits aren't being saved | Notes are editable with audit history; check the network — your save might have failed. |
| Use last formula prefilled nothing | The customer doesn't have a previous formula recorded. Start from scratch. |
| Don't see Record formula on the booking detail | You're not on Chair View — Chair View only renders when the booking is in-service (or 15 min before). Or you're on a FREE plan. |
| Linked a photo to the wrong formula | Open the photo detail and unlink, then re-link to the correct formula. |
| Summary strip missing | Cache may not have updated. Refresh the page; the cache writes inside the formula-save transaction. |
FAQ
How do I record a colour formula?
From the mobile booking detail in Chair View, tap Record formula (or Use last formula to start from the customer's previous recipe). Enter bases (up to 8), developer volume + brand, technique (roots only, global, balayage, foils, bleach wash, toner, or free-text), processing time, and notes. Save — it's locked to the booking.
Can I edit a formula after saving?
Notes can be edited (with full history kept). The formula itself — bases, developer, technique, time — is immutable once saved. To change a formula, save a new copy with the change. This keeps the per-visit audit trail clean for colour-correction sessions later.
What's 'use last formula'?
Pre-fills the new formula form with the customer's most recent recipe. Useful for repeat visits where the formula is the same or only slightly different. Always saves as a new row — never overwrites the previous.
Can formulas link to photos?
Yes. From a treatment photo, you can link it to the formula that produced it. Same-customer guarantee enforced. Makes the customer's visual history match their colour recipe history.
Are formulas visible to my customers?
No. Formulas are internal — not surfaced on the customer portal. Treatment photos can be customer-visible separately (Treatment Photos).
Do formulas affect commission or reports?
No direct effect today. The formula is a per-visit record for clinical / craft accuracy — separate from commission calculations or reporting.