In our Jira we have a custom field of type "Multi-Checkboxes". How can I search for issues which do not have a checkbox checked? Issues with nothing checked would do, since this is the only checkbox.

I can search for issues with the checkbox checked with a simple query:

```
Colour = "Red"

```

But nothing I can think of will find issues where it is not checked. I have tried the following:

```
Colour != "Red"
Colour = ""
Colour is not "Red"
Colour not in ("Red")

```