Here’s a fun way to customize your Facebook Messenger chats that can also help to clear up some confusion. It’s super-easy to change the theme of individual conversations.
To change the theme from our browser, click on the Messenger icon at the top right of the page and choose See All in Messenger from the bottom of your chat list.
At the far left, choose the conversation you want to change the colors for.
Then at the far right, select Change Theme.
Choose your preferred theme or color.
On a phone, open a conversation and tap the i at the upper right.
Tap on Theme.
Pick the theme or color.
Your chat with that individual will now its own unique look. If you chat a lot, it can be a handy way to make people stand out. For example, you could code all immediate family members or business contacts one color.
And, before you ask, there is not a way to change the overall color of every conversation… yet.