Add icon next to a menu item

Hi I use Generate press, have premium but no longer updated. I want to add a small icon to the left of one of the menu items. I managed to get an icon into the menu item by pasting the svg markup into the navigation label, but how do I give it colour and size, and make it sit in line with the text part of the menu item? I imagine css but I have no idea what to write, can someone help pretty please???????

Pss in the link provided the icon is not there because it is a live site and would look like a mess.

The page I need help with: [log in to see the link]