Slack for Mac icons: light & dark
If you're not a fan of the purple Slack for Mac icon, give these a try.
Light: https://drive.google.com/open?id=1z5X1nTJJ4X4Mv6C7BAJWfvU1SUzUASQP
Dark: https://drive.google.com/file/d/1uoIP99r4IRbDfHH_Kxp0beQFeLf1Dypi/view?usp=sharing