Slack Client has the most powerful and easy to use scripting api. On-par with Astolfo and Raven B4.
Select the theme that suits you. Slack Client has tons of visual options and color theme presets
Get Beta Builds of Slack Client. This means getting extremely early access to private bypasses, new features, and exploits on top of standard access. Beta means that you will get any version of Slack before everyone else.
Slack Client