This is where you'll as the left side color panel to color code your RAS Message. Adding a color can help people identify what the message is about if you run a color coding system in your server. Maybe all the Red messages are Required and Green Messages are Optional. Or Yellow if you want to update your status and Black if you want to opt in and out for custom role pings. You choose.
The example above can used to show what you are effecting with your color scheme here. In the photo, the colors chosen are green and red. If you want a more accurate color, choose a hex code to enter instead. Hex codes are 6 character codes that are used to describe a plethora of colors in the color spectrum. An example of two hex codes would be #000000 (Black) and #ffffff (White) Visit some color scheming website for help with choosing Hex Codes for your colors.