How do you say his or her eyes are brown in french ses means i think?

Here's how you can say "his or her eyes are brown" in French, taking into account the use of "ses" which means "his/her" in this context:

Formal:

* Ses yeux sont bruns. (This is the most direct and formal way to say it)

Informal:

* Il/Elle a les yeux bruns. (This is a more casual way to say it, using "il/elle" for "he/she")

Let me know if you'd like to see some variations or want to explore other ways to express this idea in French!