MeshCentral is great, but the icons are a little Windows 7. Luckily, the author Ylian Saint-Hilaire has added a simple way to change them. Go to your MeshCentral installation folder and navigate to \meshcentral-web\public\images – this might look something like this:
C:\Program Files\Open Source\MeshCentral\meshcentral-web\public\images
Then place the icons in the images folder. I have zipped the icons I use (see below), which are taken from the excellent FontAwesome project. Download them here.