Slack: 

Today we’re launching a new logo, as we start to refresh our look in general. We loved our old logo, and look, and know many felt the same. And yet, here we are to explain why we decided to evolve it.

The design work was done by Pentagram. 

Change is hard, and I’ve been so used to seeing the familiar Slack icon for years that this will take some getting used to. The logo itself doesn’t bother me near as much as the awful dark purple background behind it. 

Related:

• Pentagram’s ‘Range of Possibilities’ for Slack by John Gruber