# PATCH Update a mounting colour

Applies an RFC 7396 JSON Merge Patch to one mounting colour: properties omitted from the body are unchanged, and `null` clears a nullable property (`description`, the minimum sizes). Arrays are replaced wholesale, so sending `mounting_ids` replaces the whole list. Read-only and unknown fields are rejected. An empty object `{}` is a valid no-op. Requires `customisers:write`. `hexcode` and `opacity` are two views of one stored colour, so a patch naming either keeps the other. The colour cannot be cleared and `mounting_ids` cannot be emptied: either would leave a colour the storefront never shows. An `Idempotency-Key` is optional here: sending one makes the update safe to retry (an exact repeat replays the original response; the same key with a different body is a 409). The update clears the customiser's cached storefront configuration and runs the advisory language sync, and never regenerates Shopify products, product images, or the product cache.

- Source URL: https://www.signcustomiser.com/help/api/v3-patch-update-a-mounting-colour/
- Markdown URL: https://www.signcustomiser.com/help/api/v3-patch-update-a-mounting-colour.md
- Group: Customiser mounting colours
- Method: PATCH
- Path: /api/v3/customisers/{customiser_id}/mounting-colours/{mounting_colour_id}
- Auth: Bearer token
- Required scopes: `customisers:write`

## Path parameters

- customiser_id (string, required): The customiser id. Example: 1
- mounting_colour_id (string, required): The mounting colour id. Example: 14

## Body parameters

- name (string, optional): No description provided.
- description (string, optional): No description provided.
- hexcode (string, optional): No description provided.
- opacity (number, optional): No description provided.
- applied_to_visualisation (boolean, optional): No description provided.
- mounting_ids (array, optional): No description provided.
- min_width_cm (integer, optional): No description provided.
- min_height_cm (integer, optional): No description provided.
- base_price (integer, optional): No description provided.

## Request body example

```json
{
  "name": "Brushed Steel",
  "description": "A satin brushed stainless finish",
  "hexcode": "#b5b5b5",
  "opacity": 0.8,
  "applied_to_visualisation": true,
  "mounting_ids": [
    8
  ],
  "min_width_cm": 30,
  "min_height_cm": 10,
  "base_price": 500
}
```

## cURL example

```bash
curl https://web.signcustomiser.com/api/v3/customisers/1/mounting-colours/14 \
  --request PATCH \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer YOUR_API_TOKEN' \
  --header 'Content-Type: application/json' \
  --data '{
  "name": "Brushed Steel",
  "description": "A satin brushed stainless finish",
  "hexcode": "#b5b5b5",
  "opacity": 0.8,
  "applied_to_visualisation": true,
  "mounting_ids": [
    8
  ],
  "min_width_cm": 30,
  "min_height_cm": 10,
  "base_price": 500
}'
```

## Response examples

### 200 PATCH 200 example 1

```json
{
  "data": {
    "object": "mounting_colour",
    "id": 14,
    "customiser_id": 42,
    "name": "Brushed Steel",
    "description": "A satin brushed stainless finish",
    "hexcode": "#b5b5b5",
    "opacity": 0.8,
    "applied_to_visualisation": true,
    "mounting_ids": [
      8
    ],
    "min_width_cm": null,
    "min_height_cm": null,
    "min_size_rule": "any",
    "base_price": 500,
    "currency": "USD",
    "price_multiplier": 1,
    "price_multiplier_target": "base_letter_price",
    "sort_order": 1,
    "preview_image_url": null,
    "example_image_url": null,
    "created_at": "2026-08-13T00:00:00Z",
    "updated_at": "2026-08-13T00:05:00Z"
  },
  "links": {
    "self": "https://web.signcustomiser.com/api/v3/customisers/42/mounting-colours/14",
    "documentation": "https://www.signcustomiser.com/help/api/"
  },
  "meta": {
    "api_version": "v3",
    "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
  }
}
```

### 400 Malformed JSON body

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/malformed_json",
  "title": "Malformed JSON",
  "status": 400,
  "code": "malformed_json",
  "detail": "The request body is not valid JSON: Syntax error.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 401 Missing API key

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/missing_api_key",
  "title": "Missing API key",
  "status": 401,
  "code": "missing_api_key",
  "detail": "Provide a store API key as a bearer token.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 403 Insufficient scope

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/insufficient_scope",
  "title": "Insufficient scope",
  "status": 403,
  "code": "insufficient_scope",
  "detail": "This operation requires the customisers:write scope.",
  "required_scopes": [
    "customisers:write"
  ],
  "granted_scopes": [
    "customisers:read"
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 404 Unknown mounting colour

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/resource_not_found",
  "title": "Resource not found",
  "status": 404,
  "code": "resource_not_found",
  "detail": "The requested resource does not exist or does not belong to the authenticated store.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 409 Idempotency conflict

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/idempotency_key_conflict",
  "title": "Idempotency key conflict",
  "status": 409,
  "code": "idempotency_key_conflict",
  "detail": "This Idempotency-Key was already used for a different request body on this operation.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 413 Request body too large

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/request_too_large",
  "title": "Request too large",
  "status": 413,
  "code": "request_too_large",
  "detail": "The request body must not exceed 2 MiB.",
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 422 Read-only field

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/validation_failed",
  "title": "Validation failed",
  "status": 422,
  "code": "validation_failed",
  "detail": "The request payload failed validation.",
  "errors": [
    {
      "pointer": "/preview_image_url",
      "code": "prohibited",
      "detail": "The preview image url field is prohibited."
    }
  ],
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```

### 429 Option write budget exhausted

```json
{
  "type": "https://www.signcustomiser.com/help/api/problems/rate_limited",
  "title": "Too many requests",
  "status": 429,
  "code": "rate_limited",
  "detail": "You have exceeded the request limit for this API key.",
  "retry_after": 37,
  "request_id": "req_01jz9x2k7c8f3m5n6p7q8r9s0t"
}
```