How would i change this icon?

[Aravisian]

@MetaProdigy

can the image be in colour?

Yes, using Inkscape, you can easily change the color of the icon.
Please see @Storm 's excellent guide here:

How I converting icon themes

Here's a little video where I'm working with Inkscape converting one of my icon theme to a new one. It's a tedious job... [Converting Icon theme with Inkscape]

Remember that when dealing with files in Root, you will need to elevate to Root.
I Highly recommend that instead, you copy the Zorin Theme Folder to your ~/.themes directory (If ~/.themes does not exist, create it) and then make changes to that theme in your home folder. This way, if you need to revert, you can use the backup Original Theme to make a new copy.
For example:

mkdir ~/.themes/ZorinBlue-Modified

Then copy the theme you are using into that directory. To see the changes, using Gnome Tweaks or Zorin OS Appearance Settings, change Gnome-Shell theme to ZorinBlue-Modified