Sarcastic White is a theme for Slack that changes the original appearance to a dark blue-ish look and feel. We've created the theme with a clean and uncluttered design pattern in mind, to achieve optimal focus and readability for code, syntax highlighting and UI components.
Install Sarcastic White
From your desktop, click your profile picture in the top right.
Below Colors, click Create a custom theme.
Paste #161E2F,#F0F0F0,#94B7E1,#171423,#5E82AC,#FEFEFE,#94B7E1,#D9534F,#171423,#FEFEFE in the textfield labelled "Copy and paste these values to share your custom theme with others".