Set GridViewColumn.CellTemplate Rectangle Fill in Listview using Binded Value

Using a rectangle or some sort of shape I'd like to display the status of a folder in the cell template of a column in a gridview.
The gridview itself is assigned to the view property of a control.
I would like the color Green if the folder is Active / Exists

Attachment 134229

And Red if the folder is inactive / Doesn't Exist

Attachment 134231

First, each item in the list view is provided using a binding for each value (Extension ID, Sent Location), and those values come from a dataset getting it's data from a local .mdf file.

Initially i thought of achieving this by using a for loop and looping through each object and determining if each folder exists or not using the System.IO.Directory.Exists command. Honestly i find this to be a bit tedious but might be the best way to go about it so far. I'm also curious if there is a way to achieve this using a data-trigger or something along those lines to make this a bit easier.