You can do this from your desktop app or with a web browser; if you are using a mobile device, scroll up to see how to convert your mobile browser into a desktop browser.  - While in, in the Twitch chat box, type in the /color command followed by the color name.  - If you aren't a Twitch Turbo user, only Blue, Green, Red, CadetBlue, BlueViolet, YellowGreen, SeaGreen, OrangeRed, HotPink, GoldenRed, Firebrick, Chocolate, Coral are available. However, for Turbo users, you can use any color code (hex value) as all colors are available for you.