In the global styles panel's palette component, the color's hex code is
used as a `key` for the ColorIndicatorWrapper, but the hex is not
necessarily a unique identifier, unlike the `slug` attribute, which is
expected to be unique. Using slug as key prevents errors such as this:

> Warning: Encountered two children with the same key, `.$#040DE1`. Keys should be unique so that components maintain their identity across updates. Non-unique keys may cause children to be duplicated and/or omitted — the behavior is unsupported and could change in a future version.

with a palette that looks lilke this:

```json
[
	{
			"color": "#040DE1",
			"name": "Primary",
			"slug": "primary"
	},
	{
			"color": "#040DE1",
			"name": "Foreground",
			"slug": "foreground"
	},
]

```