# Colour

* [Contrast Requirements](/accessiblecontentguide/colour.md#contrast-requirements)
* [Use of Colour for Meaning](/accessiblecontentguide/colour.md#use-of-colour-for-meaning)

## Contrast Requirements

The colour that is used in the text or image must have the correct contrast ratio:

* Small Text & Images: Small-scale text and images of small-scale text must have a contrast ratio of at least 4.5:1.
* Large Text & Images: Large-scale text and images of large-scale text must have a contrast ratio of at least 3:1;
* Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content have no contrast requirement.
* Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.

**/! Note**: In order to check if a colour is okay to use, you can use a [Colour Contrast Checker](https://snook.ca/technical/colour_contrast/colour.html)

## Use of Colour for Meaning

Colour must not be used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element. For example, a calendar that only shows what day it is by highlighting the day in green would fail the standard due to there being no other way of knowing what day it is other than through visual representation.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ccsdrupalguide.uoguelph.ca/accessiblecontentguide/colour.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.