You can edit the name and color of an existing label.
On GitHub Enterprise, navigate to the main page of the repository.
Under your repository name, click Issues or Pull requests.
Above the list of issues or pull requests, click Labels.
In the labels list, next to the label you want to edit, click Edit.
In the text box, type your new label name.
Select a color for the label from the color bar. You can customize this color by editing the hexadecimal number above the color bar.
Click Save changes.