You have to edit images in the directory wp-content/themes/crown_jules_diamonds.co.uk/images/assets, for example, to change hover color for Twitter icon edit twitter.png file with some image editor (like Photoshop).
To add Instagram icon you need edit the file footer.php from line 13.
Would I go to – edit themes> footer.php,and make alterations there?
I don’t understand php; however, I am assuming you just change all the $rss to $instagram. I then just add the image to the aforementioned image directory and change “images/assets/rss.png” to the new instagram image name.
Hopefully the above makes sense and I have got things right. Changing the colours wont be a problem.