Modify UI of Helpy.io help desk system to match our Web App

We're using the open-source helpdesk / ticketing software [login to view URL] ([login to view URL]). We need an expert who can modify the colors and the theme of [login to view URL] helpdesk software to match that of our Web App's theme. All the documentation is available on-demand. We're looking for a someone who has already worked on the same and has prior experience. It is a simple job and only experienced candidates are welcome to apply.