Before you can enable AdColony Network, make sure that you already have the AdColony account. Otherwise, point your browser to the AdColony website and create one. 

After you done with the registration, create your app using AdColony Dashboard, and import AdColony Unity SDK into your project.

Now you ready to enable AdColony Mediation. 

Open plugin settings at:

Window -> Stan's Assets -> Ad Mediation -> Edit Settings

Go to the Ad Networks tab and fill AdColony setting after enabling it. As showed on the screenshot bellow.

Once you done with the Setup, you may use the AdColony Network in your Mediation Profile.