I just installed my favorite icon theme Ieos7 on my Elementary OS Freya Beta 1. Ieos7 icon theme works well on Freya like it performs on my Elementary OS Luna. Ieos7 icon theme is recommended for you who wants to have a clear look, crisp icon theme on their desktop.
If you like, you can install Ieos7 icon theme on Elementary OS Freya using this command
wget -O ieOS7-icons.deb http://goo.gl/MtQBjE
sudo dpkg -i ieOS7-icons.deb; rm ieOS7-icons.deb
Once finished, you can change the Icon theme using Elementary Tweaks. If you are having difficulties to install Elementary Tweaks on Elementary OS Freya Beta 1, you can read the solution on this post.